Rice cultivar cl181-ar

ABSTRACT

A rice cultivar designated CL181-AR is disclosed. The invention relates to the seeds of rice cultivar CL181-AR, to the plants of rice CL181-AR, to methods for producing a rice plant produced by crossing the cultivar CL181-AR with itself or another rice variety, and to methods for controlling weeds in the vicinity of plants of rice cultivar CL181-AR, which comprises increased resistance to acetohydroxyacid synthase-inhibiting herbicides. The invention further relates to hybrid rice seeds and plants produced by crossing the cultivar CL181-AR with another rice cultivar.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. patent application Ser. No.12/580,084, filed on Oct. 15, 2009, which is herein incorporated byreference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinctive rice cultivar,designated CL181-AR. All publications cited in this application areherein incorporated by reference.

Rice is an ancient agricultural crop and is today one of the principalfood crops of the world. There are two cultivated species of rice: Oryzasativa L., the Asian rice, and O. glaberrima Steud., the African rice.O. sativa L. constitutes virtually all of the world's cultivated riceand is the species grown in the United States. Three major riceproducing regions exist in the United States: the Mississippi Delta(Arkansas, Mississippi, northeast Louisiana, southeast Missouri), theGulf Coast (southwest Louisiana, southeast Texas), and the CentralValleys of California.

Rice is a semi-aquatic crop that benefits from flooded soil conditionsduring part or all of the growing season. In the United States, rice isgrown on flooded soils to optimize grain yields. Heavy clay soils orsilt loam soils with hard pan layers about 30 cm below the surface aretypical rice-producing soils because they minimize water losses fromsoil percolation. Rice production in the United States can be broadlycategorized as either dry-seeded or water-seeded. In the dry-seededsystem, rice is sown into a well-prepared seed bed with a grain drill orby broadcasting the seed and incorporating it with a disk or harrow.Moisture for seed germination is from irrigation or rainfall. Anothermethod of planting by the dry-seeded system is to broadcast the seed byairplane into a flooded field, then promptly drain the water from thefield. For the dry-seeded system, when the plants have reachedsufficient size (four-to five-leaf stage), a shallow permanent flood ofwater 5 cm to 16 cm deep is applied to the field for the remainder ofthe crop season.

In the water-seeded system, rice seed is soaked for 12 to 36 hours toinitiate germination, and the seed is broadcast by airplane into aflooded field. The seedlings emerge through a shallow flood, or thewater may be drained from the field for a short period of time toenhance seedling establishment. A shallow flood is maintained until therice approaches maturity. For both the dry-seeded and water-seededproduction systems, the fields are drained when the crop is mature, andthe rice is harvested 2 to 3 weeks later with large combines. In ricebreeding programs, breeders try to employ the production systemspredominant in their respective region. Thus, a drill-seeded breedingnursery is used by breeders in a region where rice is drill-seeded and awater-seeded nursery is used in regions where water-seeding isimportant.

Rice in the United States is classified into three primary market typesby grain size, shape, and chemical composition of the endosperm:long-grain, medium-grain and short-grain. Typical U.S. long-graincultivars cook dry and fluffy when steamed or boiled, whereas medium andshort-grain cultivars cook moist and sticky. Long-grain cultivars havebeen traditionally grown in the southern states and generally receivehigher market prices.

Although specific breeding objectives vary somewhat in the differentregions, increasing yield is a primary objective in all programs. Grainyield of rice is determined by the number of panicles per unit area, thenumber of fertile florets per panicle, and grain weight per floret.Increases in any or all of these yield components may provide amechanism to obtain higher yields. Heritable variation exists for all ofthese components, and breeders may directly or indirectly select forincreases in any of them.

There are numerous steps in the development of any novel, desirableplant germplasm. Plant breeding begins with the analysis and definitionof problems and weaknesses of the current germplasm, the establishmentof program goals, and the definition of specific breeding objectives.The next step is selection of germplasm that possess the traits to meetthe program goals. The goal is to combine in a single variety animproved combination of desirable traits from the parental germplasm.These important traits may include higher seed yield, resistance todiseases and insects, better stems and roots, tolerance to lowtemperatures, and better agronomic characteristics or grain quality.

Choice of breeding or selection methods depends on the mode of plantreproduction, the heritability of the trait(s) being improved, and thetype of cultivar used commercially (e.g., F₁ hybrid cultivar, purelinecultivar, etc.). For highly heritable traits, a choice of superiorindividual plants evaluated at a single location will be effective,whereas for traits with low heritability, selection should be based onmean values obtained from replicated evaluations of families of relatedplants. Popular selection methods commonly include pedigree selection,modified pedigree selection, mass selection, and recurrent selection, ora combination of these methods.

The complexity of inheritance influences choice of the breeding method.Backcross breeding is used to transfer one or a few favorable genes fora highly heritable trait into a desirable cultivar. This approach hasbeen used extensively for breeding disease-resistant cultivars. Variousrecurrent selection techniques are used to improve quantitativelyinherited traits controlled by numerous genes. The use of recurrentselection in self-pollinating crops depends on the ease of pollination,the frequency of successful hybrids from each pollination, and thenumber of hybrid offspring from each successful cross.

Each breeding program should include a periodic, objective evaluation ofthe efficiency of the breeding procedure. Evaluation criteria varydepending on the goal and objectives, but should include gain fromselection per year based on comparisons to an appropriate standard,overall value of the advanced breeding lines, and number of successfulcultivars produced per unit of input (e.g., per year, per dollarexpended, etc.).

Promising advanced breeding lines are thoroughly tested and compared toappropriate standards in environments representative of the commercialtarget area(s) for three or more years. The best lines are candidatesfor new commercial cultivars; those still deficient in a few traits maybe used as parents to produce new populations for further selection.

These processes, which lead to the final step of marketing anddistribution, usually take from 8 to 12 years from the time the firstcross is made and may rely on the development of improved breeding linesas precursors. Therefore, development of new cultivars is atime-consuming process that requires precise forward planning, efficientuse of resources, and a minimum of changes in direction.

A most difficult task is the identification of individuals that aregenetically superior, because for most traits the true genotypic valueis masked by other confounding plant traits or environmental factors.One method of identifying a superior plant is to observe its performancerelative to other experimental plants and to a widely grown standardcultivar. If a single observation is inconclusive, replicatedobservations provide a better estimate of its genetic worth.

The goal of rice plant breeding is to develop new, unique and superiorrice cultivars and hybrids. The breeder initially selects and crossestwo or more parental lines, followed by self-pollination and selection,producing many new genetic combinations. The breeder can theoreticallygenerate billions of different genetic combinations via crossing,selfing, and mutations. The breeder has no direct control at thecellular level. Therefore, two breeders will never develop the sameline, or even very similar lines, having the same rice traits.

Each year, the plant breeder selects the germplasm to advance to thenext generation. This germplasm is grown under unique and differentgeographical, climatic and soil conditions, and further selections arethen made, during and at the end of the growing season. The cultivarswhich are developed are unpredictable. This unpredictability is becausethe breeder's selection occurs in unique environments, with no controlat the DNA level (using conventional breeding procedures), and withmillions of different possible genetic combinations being generated. Abreeder of ordinary skill in the art cannot predict the final resultinglines he develops, except possibly in a very gross and general fashion.The same breeder cannot produce the same cultivar twice by using theexact same original parents and the same selection techniques. Thisunpredictability results in the expenditure of large amounts of researchmonies to develop superior new rice cultivars.

The development of new rice cultivars requires the development andselection of rice varieties, the crossing of these varieties andselection of superior crosses. The F₁ seed is produced by manual crossesbetween selected male-fertile parents or by using male sterilitysystems. These F₁s are selected for certain single gene traits such assemi-dwarf plant type, pubescence, awns, and apiculus color whichindicate that the seed is truly a hybrid. Additional data on parentallines, as well as the phenotype of the F₁, influence the breeder'sdecision whether to continue with the specific cross.

Pedigree breeding and recurrent selection breeding methods are used todevelop cultivars from breeding populations. Breeding programs combinedesirable traits from two or more cultivars or various broad-basedsources into breeding pools from which cultivars are developed byselfing and selection of desired phenotypes. The new cultivars areevaluated to determine which have commercial potential.

Pedigree breeding is used commonly for the improvement ofself-pollinating crops. Two parents which possess favorable,complementary traits are crossed to produce an F₁. An F₂ population isproduced by selfing one or several F₁'s. Selection of the bestindividuals may begin in the F₂ population; then, beginning in the F₃,the best individuals in the best families are selected. Replicatedtesting of families can begin in the F₄ generation to improve theeffectiveness of selection for traits with low heritability. At anadvanced stage of inbreeding (i.e., F₆ and F₇), the best lines ormixtures of phenotypically similar lines are tested for potentialrelease as new cultivars.

Mass and recurrent selections can be used to improve populations ofeither self- or cross-pollinating crops. A genetically variablepopulation of heterozygous individuals is either identified or createdby intercrossing several different parents. The best plants are selectedbased on individual superiority, outstanding progeny, or excellentcombining ability. The selected plants are intercrossed to produce a newpopulation in which further cycles of selection are continued.

Backcross breeding has been used to transfer genes for a simplyinherited, highly heritable trait into a desirable homozygous cultivaror inbred line which is the recurrent parent. The source of the trait tobe transferred is called the donor parent. The resulting plant isexpected to have the attributes of the recurrent parent (e.g., cultivar)and the desirable trait transferred from the donor parent. After theinitial cross, individuals possessing the phenotype of the donor parentare selected and repeatedly crossed (backcrossed) to the recurrentparent. The resulting plant is expected to have the attributes of therecurrent parent (e.g., cultivar) and the desirable trait transferredfrom the donor parent.

The single-seed descent procedure in the strict sense refers to plantinga segregating population, harvesting a sample of one seed per plant, andusing the one seed sample to plant the next generation. When thepopulation has been advanced from the F₂ to the desired level ofinbreeding, the plants from which lines are derived will each trace todifferent F₂ individuals. The number of plants in a population declineseach generation due to failure of some seeds to germinate or some plantsto produce at least one seed. As a result, not all of the F₂ plantsoriginally sampled in the population will be represented by a progenywhen generation advance is completed.

In a multiple-seed procedure, rice breeders commonly harvest one or moreseeds from each plant in a population and thresh them together to form abulk. Part of the bulk is used to plant the next generation and part isput in reserve. The procedure has been referred to as modifiedsingle-seed descent or the pod-bulk technique.

The multiple-seed procedure has been used to save labor at harvest. Itis considerably faster to thresh panicles with a machine than to removeone seed from each by hand for the single-seed procedure. Themultiple-seed procedure also makes it possible to plant the same numberof seeds of a population each generation of inbreeding. Enough seeds areharvested to make up for those plants that did not germinate or produceseed.

Descriptions of other breeding methods that are commonly used fordifferent traits and crops can be found in one of several referencebooks (e.g., Allard, 1960; Simmonds, 1979; Sneep, et. al, 1979; Fehr,1987).

Proper testing should detect any major faults and establish the level ofsuperiority or improvement over current cultivars. In addition toshowing superior performance, there must be a demand for a new cultivarthat is compatible with industry standards or which creates a newmarket. The introduction of a new cultivar will incur additional coststo the seed producer, the grower, processor and consumer; for specialadvertising and marketing, altered seed and commercial productionpractices, and new product utilization. The testing preceding release ofa new cultivar should take into consideration research and developmentcosts as well as technical superiority of the final cultivar. Forseed-propagated cultivars, it must be feasible to produce seed easilyand economically.

Rice, Oryza sativa L., is an important and valuable field crop. Thus, acontinuing goal of plant breeders is to develop stable, high yieldingrice cultivars that are agronomically sound. The reasons for this goalare obviously to maximize the amount of grain produced on the land usedand to supply food for both animals and humans. To accomplish this goal,the rice breeder must select and develop rice plants that have thetraits that result in superior cultivars.

The foregoing examples of the related art and limitations relatedtherewith are intended to be illustrative and not exclusive. Otherlimitations of the related art will become apparent to those of skill inthe art upon a reading of the specification.

SUMMARY OF THE INVENTION

The following embodiments and aspects thereof are described inconjunction with systems, tools and methods which are meant to beexemplary and illustrative, not limiting in scope. In variousembodiments, one or more of the above described problems have beenreduced or eliminated, while other embodiments are directed to otherimprovements.

According to the invention, there is provided a novel rice cultivardesignated CL181-AR. This invention thus relates to the seeds of ricecultivar CL181-AR, to the plants of rice CL181-AR, and to methods forproducing a rice plant produced by crossing rice CL181-AR with itself oranother rice line.

Thus, any such methods using rice variety CL181-AR are part of thisinvention: selling, backcrosses, hybrid production, crosses topopulations, and the like. All plants produced using rice varietyCL181-AR as a parent are within the scope of this invention.Advantageously, the rice variety could be used in crosses with other,different, rice plants to produce first generation (F₁) rice hybridseeds and plants with superior characteristics.

In another aspect, the present invention provides for single geneconverted plants of CL181-AR. The single transferred gene may preferablybe a dominant or recessive allele. Preferably, the single transferredgene will confer such traits as herbicide resistance, insect resistance,resistance for bacterial, fungal, or viral disease, male fertility, malesterility, enhanced nutritional quality, and industrial usage. Thesingle gene may be a naturally occurring rice gene or a transgeneintroduced through genetic engineering techniques.

In another aspect, the present invention provides regenerable cells foruse in tissue culture of rice plant CL181-AR. The tissue culture willpreferably be capable of regenerating plants having the physiologicaland morphological characteristics of the foregoing rice plant, and ofregenerating plants having substantially the same genotype as theforegoing rice plant. Preferably, the regenerable cells in such tissuecultures will be embryos, protoplasts, meristematic cells, callus,pollen, leaves, anthers, pistils, root tips, flowers, seeds, panicles,or stems. Still further, the present invention provides rice plantsregenerated from the tissue cultures of the invention.

In one aspect, the present invention provides methods for controllingweeds or undesired vegetation in the vicinity of a plant of ricecultivar CL181-AR. One method comprises applying an effective amount ofan acetohydroxyacid synthase (AHAS)-inhibiting herbicide, particularlyan imidazolinone herbicide, to the weeds and to a plant of rice cultivarCL181-AR. Another method comprises contacting a seed of rice cultivarCL181-AR before sowing and/or after pregermination with an effectiveamount of an AHAS-inhibiting herbicide, particularly an imidazolinoneherbicide. The present invention further provides seeds of rice cultivarCL181-AR treated with an effective amount of an AHAS-inhibitingherbicide, particularly an imidazolinone herbicide.

In other embodiments, the present invention provides a method forcontrolling weeds in the vicinity of rice. The method comprisescontacting the rice with an herbicide, wherein said rice belongs to anyof (a) variety CL181-AR or (b) a hybrid, derivative, or progeny ofCL181-AR that expresses the imidazolinone herbicide resistancecharacteristics of CL181-AR.

In some embodiments, the herbicide is an herbicide imidazolinone, asulfonylurea herbicide, or a combination thereof.

In one embodiment, the rice is a rice plant and said contactingcomprises applying the herbicide in the vicinity of the rice plant.

In another embodiment, the herbicide is applied to weeds in the vicinityof the rice plant.

In still further embodiments, the rice is a rice seed and saidcontacting comprises applying the herbicide to the rice seed.

In some embodiments, the present invention provides a method fortreating rice. The method comprises contacting the rice with anagronomically acceptable composition, wherein said rice belongs to anyof (a) variety CL181-AR or (b) a hybrid, derivative, or progeny ofCL181-AR that expresses the imidazolinone herbicide resistancecharacteristics of CL181-AR.

In one embodiment, the agronomically acceptable composition comprises atleast one agronomically acceptable active ingredient.

In another embodiment, the agronomically acceptable active ingredient isselected from the group consisting of fungicides, insecticides,antibiotics, stress tolerance-enhancing compounds, growth promoters,herbicides, molluscicides, rodenticides, and animal repellants, andcombinations thereof.

In addition to the exemplary aspects and embodiments described above,further aspects and embodiments will become apparent by study of thefollowing descriptions.

DEFINITIONS

In the description and tables which follow, a number of terms are used.In order to provide a clear and consistent understanding of thespecification and claims, including the scope to be given such terms,the following definitions are provided:

Alkali Spreading Value. Indicator of gelatinization temperature and anindex that measures the extent of disintegration of milled rice kernelin contact with dilute alkali solution. Standard long grains have 3 to 5Alkali Spreading Value (intermediate gelatinization temperature).

Allele. Allele is any of one or more alternative forms of a gene, all ofwhich relate to one trait or characteristic. In a diploid cell ororganism, the two alleles of a given gene occupy corresponding loci on apair of homologous chromosomes.

Apparent Amylose Percent. The most important grain characteristic thatdescribes cooking behavior in each grain class, or type, i.e., long-,medium- and short-grain. The percentage of the endosperm starch ofmilled rice that is amylose. Standard long grains contain 20% to 23%amylose. Rexmont type long grains contain 24% to 25% amylose. Short andmedium grains contain 16% to 19% amylose. Waxy rice contains 0% amylose.Amylose values will vary over environments.

Backcrossing. Backcrossing is a process in which a breeder repeatedlycrosses hybrid progeny back to one of the parents, for example, a firstgeneration hybrid F₁ with one of the parental genotypes of the F₁hybrid.

Days to 50% heading. Average number of days from emergence to the daywhen 50% of all panicles are exerted at least partially through the leafsheath. A measure of maturity.

Essentially all the physiological and morphological characteristics. Aplant having essentially all the physiological and morphologicalcharacteristics means a plant having the physiological and morphologicalcharacteristics of the cultivar, except for the characteristics derivedfrom the converted gene.

Grain Length (L). Length of a rice grain is measured as millimeters.

Grain Width (W). Width of a rice grain is measured as millimeters.

Grain Yield. Grain yield is measured in pounds per acre and at 12.0%moisture. Grain yield of rice is determined by the number of paniclesper unit area, the number of fertile florets per panicle, and grainweight per floret.

Harvest Moisture. The percent of moisture of the grain when harvested.

Length/Width (L/W) Ratio. This ratio is determined by dividing theaverage length (L) by the average width (W).

Lodging Resistance (also called Straw Strength). Lodging is measured asa subjective rating and is percentage of the plant stems leaning orfallen completely to the ground before harvest.

1000 Grain Wt. The weight of 1000 rice grains as measured in grams.

Plant Height. Plant height in centimeters is taken from soil surface tothe tip of the extended panicle at harvest.

Peak Viscosity. The maximum viscosity attained during heating when astandardized instrument-specific protocol is applied to a defined riceflour-water slurry.

Trough Viscosity. The minimum viscosity after the peak, normallyoccurring when the sample starts to cool.

Final Viscosity. Viscosity at the end of the test or cold paste.

Breakdown. The peak viscosity minus the hot paste viscosity.

Setback. Setback 1 is the final viscosity minus trough viscosity.Setback 2 is the final viscosity minus peak viscosity.

RVA Viscosity. Rapid Visco Analyzer is a widely used laboratoryinstrument to examine paste viscosity, or thickening ability of milledrice during the cooking process.

Hot Paste Viscosity. Viscosity measure of rice flour/water slurry afterbeing heated to 95° C. Lower values indicate softer and stickier cookingtypes of rice.

Cool Paste Viscosity. Viscosity measure of rice flour/water slurry afterbeing heated to 95° C. and uniformly cooled to 50° C. (AmericanAssociation of Cereal Chemist). Values less than 200 for cool pasteindicate softer cooking types of rice.

Quantitative Trait Loci (QTL). Quantitative trait loci (QTL) refer togenetic loci that control to some degree numerically representabletraits that are usually continuously distributed.

Regeneration. Regeneration refers to the development of a plant fromtissue culture.

Single Gene Converted (Conversion). Single gene converted (conversion)plant refers to plants which are developed by a plant breeding techniquecalled backcrossing wherein essentially all of the desired morphologicaland physiological characteristics of a variety are recovered in additionto the single gene transferred into the variety via the backcrossingtechnique or via genetic engineering.

DETAILED DESCRIPTION OF THE INVENTION

CL181-AR originated from a cross made at in Crowley, Louisiana in winter2001. Rice cultivar CL181-AR is a very high-yielding, short tomid-season, long-grain, Clearfield rice cultivar with maturity similarto rice cultivar ‘CL 171 AR’. Plants of CL181-AR have erect culms, greenerect leaves and glaborus lemma, palea, and leaf blades. The lemma andpalea are straw colored and the apiculi are mainly colorless with a fewpurples at maturity. Kernels of rice cultivar CL181-AR are similar tosize of kernels of ‘Wells’. Individual milled kernel weights (inmilligrams) of rice cultivar CL181-AR, ‘CL171-AR’, ‘CL161’, ‘Francis’,‘Wells’, and ‘Cocodrie’ are 18.5, 17.1, 16.4, 17.3, 18.9, and 17.8,respectively, from the Arkansas Rice Performance Trials (ARPT) conductedfrom 2007 to 2008.

CL181-AR is a semi-dwarf cultivar which is similar in height to ricecultivar CL 131. On a relative straw strength scale (0=very strongstraw, 9=very weak straw), rice cultivars CL181-AR, ‘Francis’, ‘Wells’,‘LaGrue’, ‘Drew’, ‘CL161’ and ‘Cocodrie’ rated 2, 4, 3, 5, 6, 4, and 2,respectively.

The rough rice grain yields of rice cultivar CL181-AR are very similarto rice cultivar ‘Cocodrie’ in the ARPT. In 10 ARPT tests conductedbetween 2007 to 2008, CL181-AR, ‘CL171-AR’, ‘CL161’, ‘Francis’, ‘Wells’,and ‘Cocodrie’, averaged yields of 7913, 7610, 7510, 8921, 8820, and7862 kg ha⁻¹ (120 g kg⁻¹ (12%) moisture), respectively. Milling yields(mg g⁻¹ whole kernel:mg g⁻¹ total milled rice) at 120 mg _(g) ⁻¹moisture from the ARPT conducted from 2007-2008 averaged 570:700,570:720, 600:710, 570:710, 510:710, and 620:710, for CL181-AR,‘CL171-AR’, ‘CL161’, ‘Francis’, ‘Wells’, and ‘Cocodrie’, respectively.

The cultivar has shown uniformity and stability as described in thefollowing variety description information. It has been self-pollinated asufficient number of generations with careful attention to uniformity ofplant type. The variety has been increased with continued observation toenhance uniformity.

Rice cultivar CL181-AR has the following morphologic and othercharacteristics (based primarily on data collected in Stuttgart, Ark.).

TABLE 1 VARIETY DESCRIPTION INFORMATION Plant: Grain type: Long Days tomaturity (50% heading): 91 days (range is 81-97 days; average from2007-2008 ARPT) Plant height: 85 cm (range is 74-97 cm; average from2007-2008 ARPT) Plant color (at booting): Green Culm: Angle (degreesfrom perpendicular after flowering): Erect (<30 degrees) Flag leaf(after heading): Pubescence: Glabrous Leaf angle (after heading): ErectBlade color: Green Panicle: Length: 24.9 cm (range is 20.1-31 cm) Type:Intermediate Exsertion (near maturity): 99% to 100% Axis: DroopyShattering: Low, 1% to 5% Grain (Spikelet): Awns (after full heading):Absent with a few tip awns at high fertility Apiculus color (atmaturity): Mainly straw there may be a few purples at maturity Stigmacolor: Mainly white to very light purple Lemma and palea color (atmaturity): Straw Lemma and palea pubescence: Glabrous Grain (Seed): Seedcoat (bran) color: Light-brown Endosperm type: Nonglutinous Scent:Nonscented Shape class (length/width ratio): Paddy: Long 3.63:1 Brown:Long 3.09:1 Milled: Long 3.12:1 Size: 17.9 mg/seed milled rice, 24.2mg/seed rough rice Starch amylose content: 21-23 g kg⁻¹ Alkali spreadingvalue: 3 to 5 (17 g kg⁻¹ KOH Solution) Gelatinization temperature type:Intermediate (70° C. to 75° C.) Disease Resistance: Rice blast(Magnaporthe oryzae B. Couch = Pyricularia oryzae Cavara): SusceptibleStraighthead (physiological disorder): Moderately susceptible Narrowbrown leaf spot (Cercospora oryzae Miyake): Moderately susceptibleKernel smut (Tilletia barclayana (Bref.) Sacc. & Syd. in Sacc.):Susceptible Stem rot (Magnaporthe salvinii (Catt.) R. Krause & Webster =Sclerotium oryzae Catt): Susceptible Sheath blight (Thanatephoruscucumeris (A. B. Frank) Donk = Rhizoctonia solani Kühn): Verysusceptible False smut (Ustilaginoidea virens (Cooke) Takah.):Susceptible Crown (black) sheath rot (Gaeumannomyces graminis (Sacc.)Arx & D. Olivier): Moderately susceptible Bacterial panicle blight(Burkholderia glumae): Susceptible Herbicide Resistance: Imidazolinones

This invention also is directed to methods for producing a rice plant bycrossing a first parent rice plant with a second parent rice plantwherein either the first or second parent rice plant is a rice plant ofthe line CL181-AR. Further, both first and second parent rice plants cancome from the rice cultivar CL181-AR. Still further, this invention alsois directed to methods for producing a rice cultivar CL181-AR-derivedrice plant by crossing rice cultivar CL181-AR with a second rice plantand growing the progeny seed, and repeating the crossing and growingsteps with the rice cultivar CL181-AR-derived plant from 0 to 7 times.Thus, any such methods using the rice cultivar CL181-AR are part of thisinvention: selfing, backcrosses, hybrid production, crosses topopulations, and the like. All plants produced using rice cultivarCL181-AR as a parent are within the scope of this invention, includingplants derived from rice cultivar CL181-AR. Advantageously, the ricecultivar is used in crosses with other, different, rice cultivars toproduce first generation (F₁) rice seeds and plants with superiorcharacteristics.

It should be understood that the cultivar can, through routinemanipulation of cytoplasmic or other factors, be produced in amale-sterile form. Such embodiments are also contemplated within thescope of the present claims.

As used herein, the term plant includes plant cells, plant protoplasts,plant cell tissue cultures from which rice plants can be regenerated,plant calli, plant clumps and plant cells that are intact in plants orparts of plants, such as embryos, pollen, ovules, flowers, glumes,panicles, leaves, stems, roots, root tips, anthers, pistils, and thelike.

FURTHER EMBODIMENTS OF THE INVENTION Methods for Controlling Weeds Usingthe Present Invention:

The plants of rice cultivar CL181-AR have increased tolerance orresistance to AHAS-inhibiting herbicides, particularly imidazolinoneherbicides. Thus, the plants of rice cultivar CL181-AR areherbicide-tolerant or herbicide-resistant rice plants. An“herbicide-tolerant” or a “herbicide-resistant” rice plant is a riceplant that is tolerant or resistant to at least one herbicide at a levelthat would normally kill, or inhibit the growth of, a normal orwild-type rice plant. For the present invention, the terms“herbicide-tolerant” and “herbicide-resistant” are used interchangeablyand are intended to have an equivalent meaning and an equivalent scope.Similarly, the terms “herbicide-tolerance” and “herbicide-resistance”are used interchangeably and are intended to have an equivalent meaningand an equivalent scope. Likewise, the terms “imidazolinone-tolerant”and “imidazolinone-resistant” are used interchangeably and are intendedto be of an equivalent meaning and an equivalent scope as the terms“imidazolinone-tolerance” and “imidazolinone-resistance”, respectively.

The plants of rice cultivar CL181-AR have increased resistance toAHAS-inhibiting herbicides, particularly imidazolinone herbicides, andthus find use in methods for controlling weeds. Accordingly, the presentinvention provides a method for controlling weeds in the vicinity of arice plant of the invention. The method comprises applying an effectiveamount of an herbicide to the weeds and to the rice plant of the presentinvention.

For the methods of the present invention, the preferred amount orconcentration of the herbicide is an “effective amount” or “effectiveconcentration.” “Effective amount” and “effective concentration” isintended to be an amount and concentration, respectively, that issufficient to kill or inhibit the growth of a similar, wild-type, riceplant, rice plant tissue, rice plant cell, or rice seed, but that saidamount does not kill or inhibit as severely the growth of theherbicide-resistant plants, plant tissues, plant cells, and seeds of thepresent invention. Typically, the effective amount of an herbicide is anamount that is routinely used in agricultural production systems to killweeds of interest. Such an amount is known to those of ordinary skill inthe art.

By “similar, wild-type, plant, plant tissue, plant cell or seed” isintended to be a plant, plant tissue, plant cell, or seed, respectively,that lacks the herbicide-resistance characteristics and/or particularpolynucleotide of the invention that are disclosed herein. The use ofthe term “wild-type” is not, therefore, intended to imply that a plant,plant tissue, plant cell, or other seed lacks recombinant DNA in itsgenome, and/or does not possess herbicide resistant characteristics thatare different from those disclosed herein.

The present invention provides methods for controlling weeds orundesired vegetation in the vicinity of plants of rice cultivarCL181-AR. The methods involve applying an effective amount of at leastone herbicide that interferes with the activity of the AHAS enzyme.Herbicides that are known to interfere with or inhibit the activity ofthe wild-type AHAS enzyme are known as AHAS-inhibiting herbicides, andinclude, for example, imidazolinone herbicides, sulfonylurea herbicides,triazolopyrimidine herbicides, pyrimidinyloxybenzoate herbicides,sulfonylamino-carbonyltriazolinone herbicides, and mixtures thereof.Preferably, for the present invention, the AHAS-inhibiting herbicide isan imidazolinone herbicide, or a mixture of two or more imidazolinoneherbicides.

For the present invention, the imidazolinone herbicides include, but arenot limited to, PURSUIT (imazethapyr), CADRE (imazapic), RAPTOR(imazamox), SCEPTER (imazaquin), ASSERT (imazethabenz), ARSENAL(imazapyr), a derivative of any of the aforementioned herbicides, and amixture of two or more of the aforementioned herbicides, for example,imazapyr/imazamox (ODYSSEY). More specifically, the imidazolinoneherbicide can be selected from, but is not limited to,2-(4-isopropyl-4-methyl-5-oxo-2-imidiazolin-2-yl)-nicotinic acid,[2-(4-isopropyl)-4-][methyl-5-oxo-2-imidazolin-2-yl)-3-quinolinecarboxylic]acid,[5-ethyl-2-(4-isopropyl-]4-methyl-5-oxo-2-imidazolin-2-yl)-nicotinicacid, 2-(4-isopropyl-4-methyl-5-oxo-2-(methoxymethyl)-nicotinic acid,[2-(4-isopropyl-4-methyl-5-oxo-2-]imidazolin-2-yl)-5-methylnicotinicacid, and a mixture of methyl[6-(4-isopropyl-4-]methyl-5-oxo-2-imidazolin-2-yl)-m-toluate and methyl[2-(4-isopropyl-4-methyl-5-]-p-toluate. The use of5-ethyl-2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl) -nicotinic acidand[2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-](methoxymethyl)-nicotinicacid is preferred. The use of[2-(4-isopropyl-4-](methoxymethyl)-nicotinic acid is particularlypreferred.

For the present invention, the sulfonylurea herbicides include, but arenot limited to, chlorsulfuron, metsulfuron methyl, sulfometuron methyl,chlorimuron ethyl, thifensulfuron methyl, tribenuron methyl, bensulfuronmethyl, nicosulfuron, ethametsulfuron methyl, rimsulfuron,triflusulfuron methyl, triasulfuron, primisulfuron methyl, cinosulfuron,amidosulfiuon, fluzasulfuron, imazosulfuron, pyrazosulfuron ethyl,halosulfuron, azimsulfuron, cyclosulfuron, ethoxysulfuron,flazasulfuron, flupyrsulfuron methyl, foramsulfuron, iodosulfuron,oxasulfuron, mesosulfuron, prosulfuron, sulfosulfuron, trifloxysulfuron,tritosulfuron, a derivative of any of the aforementioned herbicides, anda mixture of two or more of the aforementioned herbicides.

The triazolopyrimidine herbicides of the invention include, but are notlimited to, cloransulam, diclosulam, florasulam, flumetsulam, metosulam,and penoxsulam.

The pyrimidinyloxybenzoate herbicides of the invention include, but arenot limited to, bispyribac, pyrithiobac, pyriminobac, pyribenzoxim andpyriftalid. The sulfonylamino-carbonyltriazolinone herbicides include,but are not limited to, flucarbazone and propoxycarbazone.

It is recognized that pyrimidinyloxybenzoate herbicides are closelyrelated to the pyrimidinylthiobenzoate herbicides and are generalizedunder the heading of the latter name by the Weed Science Society ofAmerica. Accordingly, the herbicides of the present invention furtherinclude pyrimidinylthiobenzoate herbicides, including, but not limitedto, the pyrimidinyloxybenzoate herbicides described above.

By providing rice plants having increased resistance to herbicides,particularly AHAS-inhibiting herbicides, a wide variety of formulationscan be employed for protecting plants from weeds, so as to enhance plantgrowth and reduce competition for nutrients. An herbicide can be used byitself for pre-emergence, post-emergence, pre-planting and at plantingto control weeds in areas surrounding the rice plants described herein,or an imidazolinone herbicide formulation can be used that containsother additives. The herbicide can also be used as a seed treatment.Additives found in an imidazolinone herbicide formulation include otherherbicides, detergents, adjuvants, spreading agents, sticking agents,stabilizing agents, or the like. The herbicide formulation can be a wetor dry preparation and can include, but is not limited to, flowablepowders, emulsifiable concentrates and liquid concentrates. Theherbicide and herbicide formulations can be applied in accordance withconventional methods, for example, by spraying, irrigation, dusting, orthe like.

The present invention provides methods that involve the use of at leastone AHAS-inhibiting herbicide selected from the group consisting ofimidazolinone herbicides, sulfonylurea herbicides, triazolopyrimidineherbicides, pyrimidinyloxybenzoate herbicides,sulfonylamino-carbonyltriazolinone herbicides, and mixtures thereof. Inthese methods, the AHAS-inhibiting herbicide can be applied by anymethod known in the art including, but not limited to, seed treatment,soil treatment, and foliar treatment.

Prior to application, the AHAS-inhibiting herbicide can be convertedinto the customary formulations, for example solutions, emulsions,suspensions, dusts, powders, pastes and granules. The use form dependson the particular intended purpose; in each case, it should ensure afine and even distribution of the compound according to the invention.

The formulations are prepared in a known manner (see, e.g., for review,U.S. Pat. No. 3,060,084, EP-A 707 445 (for liquid concentrates),Browning, “Agglomeration”, Chemical Engineering, pp. 147-48 (Dec. 4,1967); Perry's Chemical Engineer's Handbook, 4th Ed., McGraw-Hill, NewYork, pp. 8-57 (1963), and et seq.; PCT Publication No. WO 91/13546;U.S. Pat. Nos. 4,172,714; 4,144,050; 3,299,566; 3,920,442; 5,180,587;5,232,701; and 5,208,030; G.B. Patent No. 2,095,558; Klingman, “WeedControl as a Science”, John Wiley and Sons, Inc., New York (1961); Hanceet al., Weed Control Handbook, 8th Ed., Blackwell ScientificPublications, Oxford (1989); Mollet, H., Grubemann, A., Formulationtechnology, Wiley VCH Verlag GmbH, Weinheim, Germany (2001); and D. A.Knowles, Chemistry and Technology of Agrochemical Formulations, KluwerAcademic Publishers (ISBN 0-7514-0443-8), Dordrecht (1998)), for exampleby extending the active compound with auxiliaries suitable for theformulation of agrochemicals, such as solvents and/or carriers, ifdesired, emulsifiers, surfactants and dispersants, preservatives,antifoaming agents, anti-freezing agents, for seed treatmentformulation, also optionally colorants and/or binders and/or gellingagents.

Examples of suitable solvents are water, aromatic solvents (for example,Solvesso products, xylene), paraffins (for example, mineral oilfractions), alcohols (for example, methanol, butanol, pentanol, benzylalcohol), ketones (for example, cyclohexanone, gamma-butyrolactone),pyrrolidones (NMP, NOP), acetates (glycol diacetate), glycols, fattyacid dimethylamides, fatty acids and fatty acid esters. In principle,solvent mixtures may also be used.

Examples of suitable carriers are ground natural minerals (for example,kaolins, clays, talc, chalk) and ground synthetic minerals (for example,highly disperse silica, silicates).

Suitable emulsifiers are nonionic and anionic emulsifiers (for example,polyoxyethylene fatty alcohol ethers, alkylsulfonates andarylsulfonates).

Examples of dispersants are lignin-sulfite waste liquors andmethylcellulose.

Suitable surfactants used are alkali metal, alkaline earth metal andammonium salts of lignosulfonic acid, naphthalenesulfonic acid,phenolsulfonic acid, dibutylnaphthalenesulfonic acid,alkylarylsulfonates, alkyl sulfates, alkylsulfonates, fatty alcoholsulfates, fatty acids and sulfated fatty alcohol glycol ethers,furthermore condensates of sulfonated naphthalene and naphthalenederivatives with formaldehyde, condensates of naphthalene or ofnaphthalenesulfonic acid with phenol and formaldehyde, polyoxyethyleneoctylphenol ether, ethoxylated isooctylphenol, octylphenol, nonylphenol,alkylphenol polyglycol ethers, tributylphenyl polyglycol ether,tristearylphenyl polyglycol ether, alkylaryl polyether alcohols, alcoholand fatty alcohol ethylene oxide condensates, ethoxylated castor oil,polyoxyethylene alkyl ethers, ethoxylated polyoxypropylene, laurylalcohol polyglycol ether acetal, sorbitol esters, lignosulfite wasteliquors and methylcellulose.

Substances which are suitable for the preparation of directly sprayablesolutions, emulsions, pastes or oil dispersions are mineral oilfractions of medium to high boiling point, such as, kerosene or dieseloil, furthermore coal tar oils and oils of vegetable or animal origin,aliphatic, cyclic and aromatic hydrocarbons, for example, toluene,xylene, paraffin, tetrahydronaphthalene, alkylated naphthalenes or theirderivatives, methanol, ethanol, propanol, butanol, cyclohexanol,cyclohexanone, isophorone, highly polar solvents, for example, dimethylsulfoxide, N-methylpyrrolidone or water.

Also anti-freezing agents such as glycerin, ethylene glycol, propyleneglycol and bactericides such as can be added to the formulation.

Suitable antifoaming agents are for example antifoaming agents based onsilicon or magnesium stearate.

Suitable preservatives are for example Dichlorophen andenzylalkoholhemiformal.

Seed treatment formulations may additionally comprise binders andoptionally colorants.

Binders can be added to improve the adhesion of the active materials onthe seeds after treatment. Suitable binders are block copolymers EO/POsurfactants but also polyvinylalcohols, polyvinylpyrrolidones,polyacrylates, polymethacrylates, polybutenes, polyisobutylenes,polystyrene, polyethyleneamines, polyethyleneamides, polyethyleneimines(LUPASOL, POLYMIN), polyethers, polyurethans, polyvinylacetate, tyloseand copolymers derived from these polymers.

Optionally, colorants can be included in the formulation. Suitablecolorants or dyes for seed treatment formulations are Rhodamin B, C.I.Pigment Red 112, C.I. Solvent Red 1, pigment blue 15:4, pigment blue15:3, pigment blue 15:2, pigment blue 15:1, pigment blue 80, pigmentyellow 1, pigment yellow 13, pigment red 112, pigment red 48:2, pigmentred 48:1, pigment red 57:1, pigment red 53:1, pigment orange 43, pigmentorange 34, pigment orange 5, pigment green 36, pigment green 7, pigmentwhite 6, pigment brown 25, basic violet 10, basic violet 49, acid red51, acid red 52, acid red 14, acid blue 9, acid yellow 23, basic red 10,basic red 108.

An example of a suitable gelling agent is carrageen (SATIAGEL).

Powders, materials for spreading, and dustable products can be preparedby mixing or concomitantly grinding the active substances with a solidcarrier.

Granules, for example, coated granules, impregnated granules andhomogeneous granules, can be prepared by binding the active compounds tosolid carriers. Examples of solid carriers are mineral earths such assilica gels, silicates, talc, kaolin, attaclay, limestone, lime, chalk,bole, loess, clay, dolomite, diatomaceous earth, calcium sulfate,magnesium sulfate, magnesium oxide, ground synthetic materials,fertilizers, such as, for example, ammonium sulfate, ammonium phosphate,ammonium nitrate, ureas, and products of vegetable origin, such ascereal meal, tree bark meal, wood meal and nutshell meal, cellulosepowders and other solid carriers.

In general, the formulations comprise from 0.01% to 95% by weight,preferably from 0.1 to 90% by weight, of the AHAS-inhibiting herbicide.In this case, the AHAS-inhibiting herbicides are employed in a purity of90% to 100% by weight, preferably 95% to 100% by weight (according toNMR spectrum). For seed treatment purposes, respective formulations canbe diluted 2-10 fold leading to concentrations in the ready to usepreparations of 0.01% to 60% by weight active compound by weight,preferably 0.1 to 40% by weight.

The AHAS-inhibiting herbicide can be used as such, in the form of theirformulations or the use forms prepared therefrom, for example, in theform of directly sprayable solutions, powders, suspensions ordispersions, emulsions, oil dispersions, pastes, dustable products,materials for spreading, or granules, by means of spraying, atomizing,dusting, spreading or pouring. The use forms depend entirely on theintended purposes; they are intended to ensure in each case the finestpossible distribution of the AHAS-inhibiting herbicide according to theinvention.

Aqueous use forms can be prepared from emulsion concentrates, pastes orwettable powders (sprayable powders, oil dispersions) by adding water.To prepare emulsions, pastes or oil dispersions, the substances, as suchor dissolved in an oil or solvent, can be homogenized in water by meansof a wetter, tackifier, dispersant or emulsifier. However, it is alsopossible to prepare concentrates composed of active substance, wetter,tackifier, dispersant or emulsifier and, if appropriate, solvent or oil,and such concentrates are suitable for dilution with water.

The active compound concentrations in the ready-to-use preparations canbe varied within relatively wide ranges. In general, they are from0.0001% to 10%, preferably from 0.01% to 1% per weight.

The AHAS-inhibiting herbicide may also be used successfully in theultra-low-volume process (ULV), it being possible to apply formulationscomprising over 95% by weight of active compound, or even to apply theactive compound without additives.

The following are examples of formulations:

-   1. Products for dilution with water for foliar applications. For    seed treatment purposes, such products may be applied to the seed    diluted or undiluted.

A. Water-soluble concentrates (SL, LS). Ten parts by weight of theAHAS-inhibiting herbicide are dissolved in 90 parts by weight of wateror a water-soluble solvent. As an alternative, wetters or otherauxiliaries are added. The AHAS-inhibiting herbicide dissolves upondilution with water, whereby a formulation with 10% (w/w) ofAHAS-inhibiting herbicide is obtained.

B. Dispersible concentrates (DC). Twenty parts by weight of theAHAS-inhibiting herbicide are dissolved in 70 parts by weight ofcyclohexanone with addition of 10 parts by weight of a dispersant, forexample polyvinylpyrrolidone. Dilution with water gives a dispersion,whereby a formulation with 20% (w/w) of AHAS-inhibiting herbicide isobtained.

C. Emulsifiable concentrates (EC). Fifteen parts by weight of theAHAS-inhibiting herbicide are dissolved in 7 parts by weight of xylenewith addition of calcium dodecylbenzenesulfonate and castor oilethoxylate (in each case 5 parts by weight). Dilution with water givesan emulsion, whereby a formulation with 15% (w/w) of AHAS-inhibitingherbicide is obtained.

D. Emulsions (EW, EO, ES). Twenty-five parts by weight of theAHAS-inhibiting herbicide are dissolved in 35 parts by weight of xylenewith addition of calcium dodecylbenzenesulfonate and castor oilethoxylate (in each case 5 parts by weight). This mixture is introducedinto 30 parts by weight of water by means of an emulsifier machine(e.g., Ultraturrax) and made into a homogeneous emulsion. Dilution withwater gives an emulsion, whereby a formulation with 25% (w/w) ofAHAS-inhibiting herbicide is obtained.

E. Suspensions (SC, OD, FS). In an agitated ball mill, 20 parts byweight of the AHAS-inhibiting herbicide are comminuted with addition of10 parts by weight of dispersants, wetters and 70 parts by weight ofwater or of an organic solvent to give a fine AHAS-inhibiting herbicidesuspension. Dilution with water gives a stable suspension of theAHAS-inhibiting herbicide, whereby a formulation with 20% (w/w) ofAHAS-inhibiting herbicide is obtained.

F. Water-dispersible granules and water-soluble granules (WG, SG). Fiftyparts by weight of the AHAS-inhibiting herbicide are ground finely withaddition of 50 parts by weight of dispersants and wetters and made aswater-dispersible or water-soluble granules by means of technicalappliances (for example, extrusion, spray tower, fluidized bed).Dilution with water gives a stable dispersion or solution of theAHAS-inhibiting herbicide, whereby a formulation with 50% (w/w) ofAHAS-inhibiting herbicide is obtained.

G. Water-dispersible powders and water-soluble powders (WP, SP, SS, WS).Seventy-five parts by weight of the AHAS-inhibiting herbicide are groundin a rotor-stator mill with addition of 25 parts by weight ofdispersants, wetters and silica gel. Dilution with water gives a stabledispersion or solution of the AHAS-inhibiting herbicide, whereby aformulation with 75% (w/w) of AHAS-inhibiting herbicide is obtained.

H. Gel-Formulation (GF). In an agitated ball mill, 20 parts by weight ofthe AHAS-inhibiting herbicide are comminuted with addition of 10 partsby weight of dispersants, 1 part by weight of a gelling agent wettersand 70 parts by weight of water or of an organic solvent to give a fineAHAS-inhibiting herbicide suspension. Dilution with water gives a stablesuspension of the AHAS-inhibiting herbicide, whereby a formulation with20% (w/w) of AHAS-inhibiting herbicide is obtained. This gel formulationis suitable for use as a seed treatment.

-   2. Products to be applied undiluted for foliar applications. For    seed treatment purposes, such products may be applied to the seed    diluted.

A. Dustable powders (DP, DS). Five parts by weight of theAHAS-inhibiting herbicide are ground finely and mixed intimately with 95parts by weight of finely divided kaolin. This gives a dustable producthaving 5% (w/w) of AHAS-inhibiting herbicide.

B. Granules (GR, FG, GG, MG). One-half part by weight of theAHAS-inhibiting herbicide is ground finely and associated with 95.5parts by weight of carriers, whereby a formulation with 0.5% (w/w) ofAHAS-inhibiting herbicide is obtained. Current methods are extrusion,spray-drying or the fluidized bed. This gives granules to be appliedundiluted for foliar use.

Conventional seed treatment formulations include, for example, flowableconcentrates FS, solutions LS, powders for dry treatment DS, waterdispersible powders for slurry treatment WS, water-soluble powders SSand emulsion ES and EC and gel formulation GF. These formulations can beapplied to the seed diluted or undiluted. Application to the seeds iscarried out before sowing, either directly on the seeds.

In a preferred embodiment a FS formulation is used for seed treatment.Typically, a FS formulation may comprise 1-800 g/l of active ingredient,1-200 g/l Surfactant, 0 to 200 g/l antifreezing agent, 0 to 400 g/l ofbinder, 0 to 200 g/l of a pigment and up to 1 liter of a solvent,preferably water.

For seed treatment, seeds of the rice plants of the present inventionare treated with herbicides, preferably herbicides selected from thegroup consisting of AHAS-inhibiting herbicides, such as, amidosulfuron,azimsulfuron, bensulfuron, chlorimuron, chlorsulfuron, cinosulfuron,cyclosulfamuron, ethametsulfuron, ethoxysulfuron, flazasulfuron,flupyrsulfuron, foramsulfuron, halosulfuron, imazosulfuron,iodosulfuron, mesosulfuron, metsulfuron, nicosulfuron, oxasulfuron,primisulfuron, prosulfuron, pyrazosulfuron, rimsulfuron, sulfometuron,sulfosulfuron, thifensulfuron, triasulfuron, tribenuron,trifloxysulfuron, triflusulfuron, tritosulfuron, imazamethabenz,imazamox, imazapic, imazapyr, imazaquin, imazethapyr, cloransulam,diclosulam, florasulam, flumetsulam, metosulam, penoxsulam, bispyribac,pyriminobac, propoxycarbazone, flucarbazone, pyribenzoxim, pyriftalid,pyrithiobac, and mixtures thereof, or with a formulation comprising anAHAS-inhibiting herbicide.

The term seed treatment comprises all suitable seed treatment techniquesknown in the art, such as, seed dressing, seed coating, seed dusting,seed soaking, and seed pelleting.

In accordance with one variant of the present invention, a furthersubject of the invention is a method of treating soil by theapplication, in particular into the seed drill: either of a granularformulation containing the AHAS-inhibiting herbicide as acomposition/formulation (e.g., a granular formulation, with optionallyone or more solid or liquid, agriculturally acceptable carriers and/oroptionally with one or more agriculturally acceptable surfactants.

The present invention also comprises seeds coated with or containingwith a seed treatment formulation comprising at least oneAHAS-inhibiting herbicide selected from the group consisting ofamidosulfuron, azimsulfuron, bensulfuron, chlorimuron, chlorsulfuron,cinosulfuron, cyclosulfamuron, ethametsulfuron, ethoxysulfuron,flazasulfuron, flupyrsulfuron, foramsulfuron, halosulfuron,imazosulfuron, iodosulfuron, mesosulfuron, metsulfuron, nicosulfuron,oxasulfuron, primisulfuron, prosulfuron, pyrazosulfuron, rimsulfuron,sulfometuron, sulfosulfuron, thifensulfuron, triasulfuron, tribenuron,trifloxysulfuron, triflusulfuron, tritosulfuron, imazamethabenz,imazamox, imazapic, imazapyr, imazaquin, imazethapyr, cloransulam,diclosulam, florasulam, flumetsulam, metosulam, penoxsulam, bispyribac,pyriminobac, propoxycarbazone, flucarbazone, pyribenzoxim, pyriftalid,and pyrithiobac.

The term seed embraces seeds and plant propagules of all kindsincluding, but not limited to, true seeds, seed pieces, suckers, corms,bulbs, fruit, tubers, grains, cuttings, cut shoots and the like andmeans in a preferred embodiment true seeds.

The term “coated with and/or containing” generally signifies that theactive ingredient is for the most part on the surface of the propagationproduct at the time of application, although a greater or lesser part ofthe ingredient may penetrate into the propagation product, depending onthe method of application. When the said propagation product is(re)planted, it may absorb the active ingredient.

The seed treatment application with the AHAS-inhibiting herbicide orwith a formulation comprising the AHAS-inhibiting herbicide is carriedout by spraying or dusting the seeds before sowing of the plants andbefore emergence of the plants.

In the treatment of seeds, the corresponding formulations are applied bytreating the seeds with an effective amount of the AHAS-inhibitingherbicide or a formulation comprising the AHAS-inhibiting herbicide.Herein, the application rates are generally from 0.1 g to 10 kg of thea.i. (or of the mixture of a.i. or of the formulation) per 100 kg ofseed, preferably from 1 g to 5 kg per 100 kg of seed, in particular from1 g to 2.5 kg per 100 kg of seed.

The present invention provides a method for combating undesiredvegetation or controlling weeds comprising contacting the seeds of therice plants according to the present invention before sowing and/orafter pre-germination with an AHAS-inhibiting herbicide. The method canfurther comprise sowing the seeds, for example, in soil in a field or ina potting medium in greenhouse. The method finds particular use incombating undesired vegetation or controlling weeds in the immediatevicinity of the seed.

The control of undesired vegetation is understood as meaning the killingof weeds and/or otherwise retarding or inhibiting the normal growth ofthe weeds. Weeds, in the broadest sense, are understood as meaning allthose plants which grow in locations where they are undesired.

The weeds may include, for example, dicotyledonous and monocotyledonousweeds. Dicotyledonous weeds include, but are not limited to, weeds ofthe genera: Sinapis, Lepidium, Galium, Stellaria, Matricaria, Anthemis,Galinsoga, Chenopodium, Urtica, Senecio, Amaranthus, Portulaca,Xanthium, Convolvulus, Ipomoea, Polygonum, Sesbania, Ambrosia, Cirsium,Carduus, Sonchus, Solanum, Rorippa, Rotala, Lindernia, Lamium, Veronica,Abutilon, Emex, Datura, Viola, Galeopsis, Papaver, Centaurea, Trifolium,Ranunculus, and Taraxacum. Monocotyledonous weeds include, but are notlimited to, weeds of the genera: Echinochloa, Setaria, Panicum,Digitaria, Phleum, Poa, Festuca, Eleusine, Brachiaria, Lolium, Bromus,Avena, Cyperus, Sorghum, Agropyron, Cynodon, Monochoria, Fimbristyslis,Sagittaria, Eleocharis, Scirpus, Paspalum, Ischaemum, Sphenoclea,Dactyloctenium, Agrostis, Alopecurus, and Apera.

In addition, the weeds of the present invention can include, forexample, crop plants that are growing in an undesired location. Forexample, a volunteer soybean plant that is in a field that predominantlycomprises rice plants can be considered a weed, if the soybean plant isundesired in the field of rice plants. Another example of a weed of thepresent invention is red rice which is the same species as cultivatedrice.

Transformation Techniques:

With the advent of molecular biological techniques that have allowed theisolation and characterization of genes that encode specific proteinproducts, scientists in the field of plant biology developed a stronginterest in engineering the genome of plants to contain and expressforeign genes, or additional, or modified versions of native, orendogenous, genes (perhaps driven by different promoters) in order toalter the traits of a plant in a specific manner. Such foreignadditional and/or modified genes are referred to herein collectively as“transgenes.” Over the last fifteen to twenty years, several methods forproducing transgenic plants have been developed, and the presentinvention, in particular embodiments, also relates to transformedversions of the claimed cultivar.

Culture for expressing desired structural genes and cultured cells areknown in the art. Also as known in the art, rice is transformable andregenerable such that whole plants containing and expressing desiredgenes under regulatory control may be obtained. General descriptions ofplant expression vectors and reporter genes and transformation protocolscan be found in Gruber, et al., “Vectors for Plant Transformation,” inMethods in Plant Molecular Biology and Biotechnology, Glick and ThompsonEds., CRC Press, Inc., Boca Raton, pp. 89-119 (1993)). Moreover GUSexpression vectors and GUS gene cassettes are available from Clone TechLaboratories, Inc. (Palo Alto, Calif.), while luciferase expressionvectors and luciferase gene cassettes are available from Pro Mega Corp.(Madison, Wis.). General methods of culturing plant tissues are providedfor example by Miki, et al., “Procedures for Introducing Foreign DNAinto Plants” in Methods in Plant Molecular Biology and Biotechnology,Glick and Thompson Eds., CRC Press, Inc., Boca Raton, pp. 67-88 (1993));and by Phillips, et al., “Cell-Tissue Culture and In-Vitro Manipulation”in Corn & Corn Improvement, 3rd Edition, Sprague, et al., (Eds., pp. 345387, American Society of Agronomy Inc. (1988)). Methods of introducingexpression vectors into plant tissue include the direct infection orco-cultivation of plant cells with Agrobacterium tumefaciens, describedfor example by Horsch, et al., Science, 227:1229 (1985). Descriptions ofAgrobacterium vector systems and methods for Agrobacterium-mediated genetransfer are provided by Gruber, et al., supra.

Useful methods include but are not limited to expression vectorsintroduced into plant tissues using a direct gene transfer method suchas microprojectile-mediated delivery, DNA injection, electroporation andthe like. More preferably expression vectors are introduced into planttissues using a microprojectile media delivery system with a biolisticdevice or using Agrobacterium-mediated transformation. Transformantplants obtained with the protoplasm of the invention are intended to bewithin the scope of this invention.

Plant transformation involves the construction of an expression vectorwhich will function in plant cells. Such a vector comprises DNAcomprising a gene under control of or operatively linked to a regulatoryelement (for example, a promoter). The expression vector may contain oneor more such operably linked gene/regulatory element combinations. Thevector(s) may be in the form of a plasmid, and can be used alone or incombination with other plasmids, to provide transformed rice plants,using transformation methods as described below to incorporatetransgenes into the genetic material of the rice plant(s).

Expression Vectors for Transformation: Marker Genes

Expression vectors include at least one genetic marker, operably linkedto a regulatory element (a promoter, for example) that allowstransformed cells containing the marker to be either recovered bynegative selection, i.e., inhibiting growth of cells that do not containthe selectable marker gene, or by positive selection, i.e., screeningfor the product encoded by the genetic marker. Many commonly usedselectable marker genes for plant transformation are well known in thetransformation arts, and include, for example, genes that code forenzymes that metabolically detoxify a selective chemical agent which maybe an antibiotic or an herbicide, or genes that encode an altered targetwhich is insensitive to the inhibitor. A few positive selection methodsare also known in the art.

One commonly used selectable marker gene for plant transformation is theneomycin phosphotransferase II (nptll) gene, isolated from transposonTn5, which when placed under the control of plant regulatory signalsconfers resistance to kanamycin. Fraley, et al., Proc. Natl. Acad. Sci.U.S.A., 80:4803 (1983). Another commonly used selectable marker gene isthe hygromycin phosphotransferase gene which confers resistance to theantibiotic hygromycin. Vanden Elzen, et al., Plant Mol. Biol., 5:299(1985).

Additional selectable marker genes of bacterial origin that conferresistance to antibiotics include gentamycin acetyl transferase,streptomycin phosphotransferase, and aminoglycoside-3′-adenyltransferase, the bleomycin resistance determinant. Hayford, et al.,Plant Physiol., 86:1216 (1988); Jones, et al., Mol. Gen. Genet., 210:86(1987); Svab, et al., Plant Mol. Biol., 14:197 (1990); Hille, et al.,Plant Mol. Biol., 7:171 (1986). Other selectable marker genes conferresistance to herbicides such as glyphosate, glufosinate or bromoxynil.Comai, et al., Nature, 317:741-744 (1985); Gordon-Kamm, et al., PlantCell, 2:603-618 (1990); and Stalker, et al., Science, 242:419-423(1988).

Selectable marker genes for plant transformation not of bacterial origininclude, for example, mouse dihydrofolate reductase, plant5-enolpyruvylshikimate-3-phosphate synthase, and plant acetolactatesynthase. Eichholtz, et al., Somatic Cell Mol. Genet., 13:67 (1987);Shah, et al., Science, 233:478 (1986); Charest, et al., Plant Cell Rep.,8:643 (1990).

Another class of marker genes for plant transformation requiresscreening of presumptively transformed plant cells rather than directgenetic selection of transformed cells for resistance to a toxicsubstance such as an antibiotic. These genes are particularly useful toquantify or visualize the spatial pattern of expression of a gene inspecific tissues and are frequently referred to as reporter genesbecause they can be fused to a gene or gene regulatory sequence for theinvestigation of gene expression. Commonly used genes for screeningpresumptively transformed cells include β-glucuronidase (GUS,β-galactosidase, luciferase and chloramphenicol acetyltransferase.Jefferson, R. A., Plant Mol. Biol. Rep., 5:387 (1987); Teeri, et al.,EMBO J., 8:343 (1989); Koncz, et al., Proc. Natl. Acad. Sci U.S.A.,84:131 (1987); DeBlock, et al., EMBO J., 3:1681 (1984). Another approachto the identification of relatively rare transformation events has beenuse of a gene that encodes a dominant constitutive regulator of the Zeamays anthocyanin pigmentation pathway. Ludwig, et al., Science, 247:449(1990).

In vivo methods for visualizing GUS activity that do not requiredestruction of plant tissue are available. Molecular Probes Publication2908, IMAGENE GREEN, pp. 1-4 (1993) and Naleway, et al., J. Cell Biol.,115:151a (1991). However, these in vivo methods for visualizing GUSactivity have not proven useful for recovery of transformed cellsbecause of low sensitivity, high fluorescent backgrounds and limitationsassociated with the use of luciferase genes as selectable markers.

More recently, a gene encoding Green Fluorescent Protein (GFP) has beenutilized as a marker for gene expression in prokaryotic and eukaryoticcells. Chalfie, et al., Science, 263:802 (1994). GFP and mutants of GFPmay be used as screenable markers.

Expression Vectors for Transformation: Promoters

Genes included in expression vectors must be driven by nucleotidesequence comprising a regulatory element, for example, a promoter.Several types of promoters are now well known in the transformationarts, as are other regulatory elements that can be used alone or incombination with promoters.

As used herein, “promoter” includes reference to a region of DNAupstream from the start of transcription and involved in recognition andbinding of RNA polymerase and other proteins to initiate transcription.A “plant promoter” is a promoter capable of initiating transcription inplant cells. Examples of promoters under developmental control includepromoters that preferentially initiate transcription in certain tissues,such as leaves, roots, seeds, fibers, xylem vessels, tracheitis, orsclerenchyma. Such promoters are referred to as “tissue-preferred.”Promoters which initiate transcription only in certain tissue arereferred to as “tissue-specific.” A “cell type” specific promoterprimarily drives expression in certain cell types in one or more organs,for example, vascular cells in roots or leaves. An “inducible” promoteris a promoter which is under environmental control. Examples ofenvironmental conditions that may effect transcription by induciblepromoters include anaerobic conditions or the presence of light.Tissue-specific, tissue-preferred, cell type specific, and induciblepromoters constitute the class of “non-constitutive” promoters. A“constitutive” promoter is a promoter which is active under mostenvironmental conditions.

A. Inducible Promoters—An inducible promoter is operably linked to agene for expression in rice. Optionally, the inducible promoter isoperably linked to a nucleotide sequence encoding a signal sequencewhich is operably linked to a gene for expression in rice. With aninducible promoter the rate of transcription increases in response to aninducing agent.

Any inducible promoter can be used in the instant invention. See, Ward,et al., Plant Mol. Biol., 22:361-366 (1993). Exemplary induciblepromoters include, but are not limited to, that from the ACEI systemwhich responds to copper (Meft, et al., PNAS, 90:4567-4571 (1993)); Intgene from maize which responds to benzenesulfonamide herbicide safeners(Hershey, et al., Mol. Gen Genetics, 227:229-237 (1991) and Gatz, etal., Mol. Gen. Genetics, 243:32-38 (1994)) or Tet repressor from Tn10(Gatz, et al., Mol. Gen. Genetics, 227:229-237 (1991)). A particularlypreferred inducible promoter is a promoter that responds to an inducingagent to which plants do not normally respond. An exemplary induciblepromoter is the inducible promoter from a steroid hormone gene, thetranscriptional activity of which is induced by a glucocorticosteroidhormone (Schena, et al., Proc. Natl. Acad. Sci. USA., 88:0421 (1991)).

B. Constitutive Promoters—A constitutive promoter is operably linked toa gene for expression in rice or the constitutive promoter is operablylinked to a nucleotide sequence encoding a signal sequence which isoperably linked to a gene for expression in rice.

Many different constitutive promoters can be utilized in the instantinvention. Exemplary constitutive promoters include, but are not limitedto, the promoters from plant viruses such as the 35S promoter from CaMV(Odell, et al., Nature, 313:810-812 (1985)) and the promoters from suchgenes as rice actin (McElroy, et al., Plant Cell, 2:163-171 (1990));ubiquitin (Christensen, et al., Plant Mol. Biol., 12:619-632 (1989) andChristensen, et al., Plant Mol. Biol., 18:675-689 (1992)); pEMU (Last,et al., Theor. Appl. Genet., 81:581-588 (1991)); MAS (Velten, et al.,EMBO J, 3:2723-2730 (1984)); and maize H3 histone (Lepetit, et al., Mol.Gen. Genetics, 231:276-285 (1992) and Atanassova, et al., Plant Journal2 (3): 291-300 (1992)).

The ALS promoter, Xbal/Ncol fragment 5′ to the Brassica napus ALS3structural gene (or a nucleotide sequence similarity to said Xbal/Ncolfragment), represents a particularly useful constitutive promoter. See,PCT Appl. No. WO 96/30530.

C. Tissue-specific or Tissue-preferred Promoters—A tissue-specificpromoter is operably linked to a gene for expression in rice.Optionally, the tissue-specific promoter is operably linked to anucleotide sequence encoding a signal sequence which is operably linkedto a gene for expression in rice. Plants transformed with a gene ofinterest operably linked to a tissue-specific promoter produce theprotein product of the transgene exclusively, or preferentially, in aspecific tissue.

Any tissue-specific or tissue-preferred promoter can be utilized in theinstant invention. Exemplary tissue-specific or tissue-preferredpromoters include, but are not limited to, a root-preferred promoter,such as that from the phaseolin gene (Murai, et al., Science, 23:476-482(1983) and Sengupta-Gopalan, et al., Proc. Natl. Acad. Sci. U.S.A.,82:3320-3324 (1985)); a leaf-specific and light-induced promoter such asthat from cab or rubisco (Simpson, et al., EMBO J., 4(11):2723-2729(1985) and Timko, et al., Nature, 318:579-582 (1985)); ananther-specific promoter such as that from LAT52 (Twell, et al., Mol.Gen. Genetics, 217:240-245 (1989)); a pollen-specific promoter such asthat from Zm13 (Guerrero, et al., Mol. Gen. Genetics, 244:161-168(1993)) or a microspore-preferred promoter such as that from apg (Twell,et al., Sex. Plant Reprod., 6:217-224 (1993)).

Signal Sequences for Targeting Proteins to Sub-Cellular Compartments

Transport of protein produced by transgenes to a subcellular compartmentsuch as the chloroplast, vacuole, peroxisome, glyoxysome, cell wall, ormitochondrion, or for secretion into the apoplast, is accomplished bymeans of operably linking the nucleotide sequence encoding a signalsequence to the 5′ and/or 3′ region of a gene encoding the protein ofinterest. Targeting sequences at the 5′ and/or 3′ end of the structuralgene may determine, during protein synthesis and processing, where theencoded protein is ultimately compartmentalized.

The presence of a signal sequence directs a polypeptide to either anintracellular organelle or subcellular compartment or for secretion tothe apoplast. Many signal sequences are known in the art. See, forexample, Becker, et al., Plant Mol. Biol., 20:49 (1992); Close, P. S.,Master's Thesis, Iowa State University (1993); Knox, C., et al., PlantMol. Biol., 9:3-17 (1987); Lerner, et al., Plant Physiol., 91:124-129(1989); Fontes, et al., Plant Cell, 3:483-496 (1991); Matsuoka, et al.,Proc. Natl. Acad. Sci., 88:834 (1991); Gould, et al., J. Cell. Biol.,108:1657 (1989); Creissen, et al., Plant J., 2:129 (1991); Kalderon, etal., Cell, 39:499-509 (1984); Steifel, et al., Plant Cell, 2:785-793(1990).

Foreign Protein Genes and Agronomic Genes

With transgenic plants according to the present invention, a foreignprotein can be produced in commercial quantities. Thus, techniques forthe selection and propagation of transformed plants, which are wellunderstood in the art, yield a plurality of transgenic plants which areharvested in a conventional manner, and a foreign protein then can beextracted from a tissue of interest or from total biomass. Proteinextraction from plant biomass can be accomplished by known methods whichare discussed, for example, by Heney and Orr, Anal. Biochem., 114:92-6(1981).

According to a preferred embodiment, the transgenic plant provided forcommercial production of foreign protein is rice. In another preferredembodiment, the biomass of interest is seed. For the relatively smallnumber of transgenic plants that show higher levels of expression, agenetic map can be generated, primarily via conventional RFLP, PCR, andSSR analysis, which identifies the approximate chromosomal location ofthe integrated DNA molecule. For exemplary methodologies in this regard,see Methods in Plant Molecular Biology and Biotechnology, Glick andThompson Eds., CRC Press, Inc., Boca Raton, pp. 269-284 (1993)). Mapinformation concerning chromosomal location is useful for proprietaryprotection of a subject transgenic plant. If unauthorized propagation isundertaken and crosses made with other germplasm, the map of theintegration region can be compared to similar maps for suspect plants,to determine if the latter have a common parentage with the subjectplant. Map comparisons would involve hybridizations, RFLP, PCR, SSR, andsequencing, all of which are conventional techniques.

Through the transformation of rice, the expression of genes can bealtered to enhance disease resistance, insect resistance, herbicideresistance, agronomic quality and other traits. Transformation can alsobe used to insert DNA sequences which control or help controlmale-sterility. DNA sequences native to rice as well as non-native DNAsequences can be transformed into rice and used to alter levels ofnative or non-native proteins. Various promoters, targeting sequences,enhancing sequences, and other DNA sequences can be inserted into thegenome for the purpose of altering the expression of proteins. Reductionof the activity of specific genes (also known as gene silencing, or genesuppression) is desirable for several aspects of genetic engineering inplants.

Many techniques for gene silencing are well-known to one of skill in theart, including, but not limited to, knock-outs (such as by insertion ofa transposable element such as mu (Vicki Chandler, The Maize Handbook,ch. 118, Springer-Verlag (1994)) or other genetic elements such as aFRT, Lox, or other site specific integration site, antisense technology(see, e.g., Sheehy, et al., PNAS USA, 85:8805-8809 (1988); and U.S. Pat.Nos. 5,107,065; 5,453,566; and 5,759,829); co-suppression (e.g., Taylor,Plant Cell, 9:1245 (1997); Jorgensen, Trends Biotech., 8(12):340-344(1990); Flavell, PNAS USA, 91:3490-3496 (1994); Finnegan, et al.,Bio/Technology, 12: 883-888 (1994); and Neuhuber, et al., Mol. Gen.Genet., 244:230-241 (1994)); RNA interference (Napoli, et al., PlantCell, 2:279-289 (1990); U.S. Pat. No. 5,034,323; Sharp, Genes Dev.,13:139-141 (1999); Zamore, et al., Cell, 101:25-33 (2000); andMontgomery, et al., PNAS USA, 95:15502-15507 (1998)); virus-induced genesilencing (Burton, et al., Plant Cell, 12:691-705 (2000); and Baulcombe,Curr. Op. Plant Bio., 2:109-113 (1999)); target-RNA-specific ribozymes(Haseloff, et al., Nature, 334: 585-591 (1988)); hairpin structures(Smith, et al., Nature, 407:319-320 (2000); WO 99/53050; and WO98/53083); MicroRNA (Aukerman & Sakai, Plant Cell, 15:2730-2741 (2003));ribozymes (Steinecke, et al., EMBO J., 11:1525 (1992); and Perriman, etal., Antisense Res. Dev., 3:253 (1993)); oligonucleotide mediatedtargeted modification (e.g., PCT Publication Nos. WO 03/076574 and WO99/25853); Zn-finger targeted molecules (e.g., PCT Publication Nos. WO01/52620; WO 03/048345; and WO 00/42219); and other methods orcombinations of the above methods known to those of skill in the art.

Likewise, by means of the present invention, agronomic genes can beexpressed in transformed plants. More particularly, plants can begenetically engineered to express various phenotypes of agronomicinterest. Exemplary genes implicated in this regard include, but are notlimited to, those categorized below:

-   1. Genes That Confer Resistance to Pests or Disease and That Encode:

A. Plant disease resistance genes. Plant defenses are often activated byspecific interaction between the product of a disease resistance gene(R) in the plant and the product of a corresponding avirulence (Avr)gene in the pathogen. A plant cultivar can be transformed with clonedresistance gene to engineer plants that are resistant to specificpathogen strains. See, for example, Jones, et al., Science, 266:789(1994) (cloning of the tomato Cf-9 gene for resistance to Cladosporiumfulvum); Martin, et al., Science, 262:1432 (1993) (tomato Pto gene forresistance to Pseudomonas syringae pv. tomato encodes a protein kinase);Mindrinos, et al., Cell, 78:1089 (1994) (Arabidopsis RSP2 gene forresistance to Pseudomonas syringae); McDowell & Woffenden, TrendsBiotechnol., 21(4): 178-83 (2003); and Toyoda, et al., Transgenic Res.,11 (6):567-82 (2002).

B. A Bacillus thuringiensis protein, a derivative thereof or a syntheticpolypeptide modeled thereon. See, for example, Geiser, et al., Gene,48:109 (1986), who disclose the cloning and nucleotide sequence of a Btδ-endotoxin gene. Moreover, DNA molecules encoding δ-endotoxin genes canbe purchased from American Type Culture Collection, Manassas, Va., forexample, under ATCC Accession Nos. 40098, 67136, 31995, and 31998.

C. A lectin. See, for example, the disclosure by Van Damme, et al.,Plant Molec. Biol., 24:25 (1994), who disclose the nucleotide sequencesof several Clivia miniata mannose-binding lectin genes.

D. A vitamin-binding protein such as avidin. See, PCT Appl. No. US93/06487. The application teaches the use of avidin and avidinhomologues as larvicides against insect pests.

E. An enzyme inhibitor, for example, a protease or proteinase inhibitoror an amylase inhibitor. See, for example, Abe, et al., J. Biol. Chem.,262:16793 (1987) (nucleotide sequence of rice cysteine proteinaseinhibitor); Huub, et al., Plant Molec. Biol., 21:985 (1993) (nucleotidesequence of cDNA encoding tobacco proteinase inhibitor I); Sumitani, etal., Biosci. Biotech. Biochem., 57:1243 (1993) (nucleotide sequence ofStreptomyces nitrosporeus α-amylase inhibitor).

F. An insect-specific hormone or pheromone such as an ecdysteroid andjuvenile hormone, a variant thereof, a mimetic based thereon, or anantagonist or agonist thereof. See, for example, the disclosure byHammock, et al., Nature, 344:458 (1990), of baculovirus expression ofcloned juvenile hormone esterase, an inactivator of juvenile hormone.

G. An insect-specific peptide or neuropeptide which, upon expression,disrupts the physiology of the affected pest. For example, see thedisclosures of Regan, J. Biol. Chem., 269:9 (1994) (expression cloningyields DNA coding for insect diuretic hormone receptor), and Pratt, etal., Biochem. Biophys. Res. Comm., 163:1243 (1989) (an allostatin isidentified in Diploptera puntata). See also, U.S. Pat. No. 5,266,317 toTomalski, et al., who disclose genes encoding insect-specific, paralyticneurotoxins.

H. An insect-specific venom produced in nature by a snake, a wasp, etc.For example, see Pang, et al., Gene, 116:165 (1992), for disclosure ofheterologous expression in plants of a gene coding for a scorpioninsectotoxic peptide.

I. An enzyme responsible for a hyper-accumulation of a monoterpene, asesquiterpene, a steroid, a hydroxamic acid, a phenylpropanoidderivative or another non-protein molecule with insecticidal activity.

J. An enzyme involved in the modification, including thepost-translational modification, of a biologically active molecule; forexample, a glycolytic enzyme, a proteolytic enzyme, a lipolytic enzyme,a nuclease, a cyclase, a transaminase, an esterase, a hydrolase, aphosphatase, a kinase, a phosphorylase, a polymerase, an elastase, achitinase, and a glucanase, whether natural or synthetic. See, PCTPublication No. WO 93/02197 in the name of Scott, et al., whichdiscloses the nucleotide sequence of a callase gene. DNA molecules whichcontain chitinase-encoding sequences can be obtained, for example, fromthe ATCC under Accession Nos. 39637 and 67152. See also, Kramer, et al.,Insect Biochem. Molec. Biol., 23:691 (1993), who teach the nucleotidesequence of a cDNA encoding tobacco hornworm chitinase, and Kawalleck,et al., Plant Molec. Biol., 21:673 (1993), who provide the nucleotidesequence of the parsley ubi4-2 polyubiquitin gene.

K. A molecule that stimulates signal transduction. For example, see thedisclosure by Botella, et al., Plant Molec. Biol., 24:757 (1994), ofnucleotide sequences for mung bean calmodulin cDNA clones, and Griess,et al., Plant Physiol., 104:1467 (1994), who provide the nucleotidesequence of a maize calmodulin cDNA clone.

L. A hydrophobic moment peptide. See, PCT Publication No. WO 95/16776(disclosure of peptide derivatives of Tachyplesin which inhibit fungalplant pathogens) and PCT Publication No. WO 95/18855 (teaches syntheticantimicrobial peptides that confer disease resistance), the respectivecontents of which are hereby incorporated by reference.

M. A membrane permease, a channel former or a channel blocker. Forexample, see the disclosure of Jaynes, et al., Plant Sci, 89:43 (1993),of heterologous expression of a cecropin-β, lytic peptide analog torender transgenic tobacco plants resistant to Pseudomonas solanacearum.

N. A viral-invasive protein or a complex toxin derived therefrom. Forexample, the accumulation of viral coat proteins in transformed plantcells imparts resistance to viral infection and/or disease developmenteffected by the virus from which the coat protein gene is derived, aswell as by related viruses. See, Beachy, et al., Ann. Rev. Phytopathol.,28:451 (1990). Coat protein-mediated resistance has been conferred upontransformed plants against alfalfa mosaic virus, cucumber mosaic virus,tobacco streak virus, potato virus X, potato virus Y, tobacco etchvirus, tobacco rattle virus, and tobacco mosaic virus. Id.

O. An insect-specific antibody or an immunotoxin derived therefrom.Thus, an antibody targeted to a critical metabolic function in theinsect gut would inactivate an affected enzyme, killing the insect. Cf.Taylor, et al., Abstract #497, Seventh International Symposium onMolecular Plant-Microbe Interactions (Edinburgh, Scotland (1994))(enzymatic inactivation in transgenic tobacco via production ofsingle-chain antibody fragments).

P. A virus-specific antibody. See, for example, Tavladoraki, et al.,Nature, 366:469 (1993), who show that transgenic plants expressingrecombinant antibody genes are protected from virus attack.

Q. A developmental-arrestive protein produced in nature by a pathogen ora parasite. Thus, fungal endo-α-1,4-D-polygalacturonases facilitatefungal colonization and plant nutrient release by solubilizing plantcell wall homo-α-1,4-D-galacturonase. See, Lamb, et al., Bio/Technology,10:1436 (1992). The cloning and characterization of a gene which encodesa bean endopolygalacturonase-inhibiting protein is described by Toubart,et al., Plant J., 2:367 (1992).

R. A developmental-arrestive protein produced in nature by a plant. Forexample, Logemann, et al., Bio/Technology, 10:305 (1992), have shownthat transgenic plants expressing the barley ribosome-inactivating genehave an increased resistance to fungal disease.

S. Genes involved in the Systemic Acquired Resistance (SAR) Responseand/or the pathogenesis-related genes. Briggs, S., Current Biology, 5(2)(1995); Pieterse & Van Loon, Curr. Opin. Plant Bio., 7(4):456-64 (2004)and Somssich, Cell, 113(7):815-6 (2003).

T. Antifungal genes. See, Cornelissen and Melchers, Plant Physiol.,101:709-712 (1993); Parijs, et al., Planta, 183:258-264 (1991) andBushnell, et al., Can. J. of Plant Path., 20(2):137-149 (1998). Seealso, U.S. Pat. No. 6,875,907.

U. Detoxification genes, such as for fumonisin, beauvericin,moniliformin, and zearalenone, and their structurally relatedderivatives. For example, see U.S. Pat. No. 5,792,931.

V. Cystatin and cysteine proteinase inhibitors. See U.S. Pat. No.7,205,453.

W. Defensin genes. See PCT Publication No. WO 03/000863 and U.S. Pat.No. 6,911,577.

-   2. Genes That Confer Resistance to an Herbicide, for Example:

A. An herbicide that inhibits the growing point or meristem, such as animidazolinone or a sulfonylurea. Exemplary genes in this category codefor mutant ALS and AHAS enzyme as described, for example, by Lee, etal., EMBO 1, 7:1241 (1988) and Miki, et al., Theor. Appl. Genet., 80:449(1990), respectively.

B. Glyphosate (resistance conferred by mutant5-enolpyruvlshikimate-3-phosphate synthase (EPSP) and aroA genes,respectively) and other phosphono compounds such as glufosinate(phosphinothricin acetyl transferase (PAT) and Streptomyceshygroscopicus PAT, bar, genes), and pyridinoxy or phenoxy propionicacids and cyclohexones (ACCase inhibitor-encoding genes). See, forexample, U.S. Pat. No. 4,940,835 to Shah, et al., which discloses thenucleotide sequence of a form of EPSP which can confer glyphosateresistance. A DNA molecule encoding a mutant aroA gene can be obtainedunder ATCC Accession No. 39256, and the nucleotide sequence of themutant gene is disclosed in U.S. Pat. No. 4,769,061 to Comai. EuropeanPat. Appl. No. 0 333 033 to Kumada, et al. and U.S. Pat. No. 4,975,374to Goodman, et al., disclose nucleotide sequences of glutaminesynthetase genes which confer resistance to herbicides such asL-phosphinothricin. The nucleotide sequence of a PAT gene is provided inEuropean Pat. Appl. No. 0 242 246 to Leemans, et al. DeGreef, et al.,Bio/Technology, 7:61 (1989), describe the production of transgenicplants that express chimeric bar genes coding for PAT activity.Exemplary of genes conferring resistance to phenoxy propionic acids andcyclohexones, such as sethoxydim and haloxyfop are the Acc1-S1, Acc1-S2,and Acc1-S3 genes described by Marshall, et al., Theor. Appl. Genet.,83:435 (1992).

C. An herbicide that inhibits photosynthesis, such as a triazine (psbAand gs+ genes) or a benzonitrile (nitrilase gene). Przibilla, et al.,Plant Cell, 3:169 (1991), describe the transformation of Chlamydomonaswith plasmids encoding mutant psbA genes. Nucleotide sequences fornitrilase genes are disclosed in U.S. Pat. No. 4,810,648 to Stalker, andDNA molecules containing these genes are available under ATCC AccessionNos. 53435, 67441, and 67442. Cloning and expression of DNA coding for aglutathione S-transferase is described by Hayes, et al., Biochem.285:173 (1992).

-   3. Genes That Confer or Contribute to a Value-Added Trait, such as:

A. Modified fatty acid metabolism, for example, by transforming a plantwith an antisense gene of stearyl-ACP desaturase to increase stearicacid content of the plant. See, Knultzon, et al., Proc. Natl. Acad. Sci.U.S.A., 89:2624 (1992).

B. Decreased phytate content. 1) Introduction of a phytase-encoding genewould enhance breakdown of phytate, adding more free phosphate to thetransformed plant. For example, see, Van Hartingsveldt, et al., Gene,127:87 (1993), for a disclosure of the nucleotide sequence of anAspergillus niger phytase gene; 2) A gene could be introduced thatreduced phytate content. In maize, this, for example, could beaccomplished by cloning and then reintroducing DNA associated with thesingle allele which is responsible for maize mutants characterized bylow levels of phytic acid. See, Raboy, et al., Maydica, 35:383 (1990).

C. Modified carbohydrate composition effected, for example, bytransforming plants with a gene coding for an enzyme that alters thebranching pattern of starch. See, Shiroza, et al., J. Bacteol., 170:810(1988) (nucleotide sequence of Streptococcus mutantsfructosyltransferase gene); Steinmetz, et al., Mol. Gen. Genet., 20:220(1985) (nucleotide sequence of Bacillus subtilis levansucrase gene);Pen, et al., Bio/Technology, 10:292 (1992) (production of transgenicplants that express Bacillus lichenifonnis α-amylase); Elliot, et al.,Plant Molec. Biol., 21:515 (1993) (nucleotide sequences of tomatoinvertase genes); Søgaard, et al., J. Biol. Chem., 268:22480 (1993)(site-directed mutagenesis of barley α-amylase gene); and Fisher, etal., Plant Physiol., 102:1045 (1993) (maize endosperm starch branchingenzyme II).

-   4. Genes That Control Male Sterility:

There are several available methods of conferring genetic male sterilityavailable, such as multiple mutant genes at separate locations withinthe genome that confer male sterility, as disclosed in U.S. Pat. Nos.4,654,465 and 4,727,219 to Brar, et al., and chromosomal translocationsas described by Patterson in U.S. Pat. Nos. 3,861,709 and 3,710,511. Inaddition to these methods, Albertsen, et al., U.S. Pat. No. 5,432,068,describes a system of nuclear male sterility which includes: identifyinga gene which is critical to male fertility; silencing this native genewhich is critical to male fertility; removing the native promoter fromthe essential male fertility gene and replacing it with an induciblepromoter; inserting this genetically engineered gene back into theplant; and thus creating a plant that is male sterile because theinducible promoter is not “on” resulting in the male fertility gene notbeing transcribed. Fertility is restored by inducing, or turning “on,”the promoter, which in turn allows the gene that confers male fertilityto be transcribed.

A. A tapetum-specific gene, RTS, a rice anther-specific gene is requiredfor male fertility and its promoter sequence directs tissue-specificgene expression in different plant species. Luo, Hong, et. al., PlantMolecular Biology., 62(3): 397-408(12) (2006). Introduction of adeacetylase gene under the control of a tapetum-specific promoter andwith the application of the chemical N-Ac-PPT. See PCT Publication No.WO 01/29237.

B. Introduction of various stamen-specific promoters. Riceanther-specific promoters which are of particular utility in theproduction of transgenic male-sterile monocots and plants for restoringtheir fertility. See, U.S. Pat. No. 5,639,948. See also, PCT PublicationNos. WO 92/13956 and WO 92/13957.

C. Introduction of the barnase and the barstar genes. See, Paul, et al.,Plant Mol. Biol., 19:611-622 (1992).

For additional examples of nuclear male and female sterility systems andgenes, see also, U.S. Pat. Nos. 5,859,341, 6,297,426, 5,478,369,5,824,524, 5,850,014, and 6,265,640. See also, Hanson, Maureen R., et.al., “Interactions of Mitochondrial and Nuclear Genes That Affect MaleGametophyte Development,” Plant Cell., 16:S154-S169 (2004), all of whichare hereby incorporated by reference.

-   5. Genes That Create a Site for Site Specific DNA Integration:

This includes the introduction of FRT sites that may be used in theFLP/FRT system and/or Lox sites that may be used in the Cre/Loxp system.For example, see, Lyznik, et al., Site-Specific Recombination forGenetic Engineering in Plants, Plant Cell Rep, 21:925-932 (2003) and PCTPublication No. WO 99/25821, which are hereby incorporated by reference.Other systems that may be used include the Gin recombinase of phage Mu(Maeser, et al. (1991); Vicki Chandler, The Maize Handbook, ch. 118,Springer-Verlag (1994), the Pin recombinase of E. coli (Enomoto, et al.(1983)), and the R/RS system of the pSR1 plasmid (Araki, et al. (1992)).

-   6. Genes That Affect Abiotic Stress Resistance:

Genes that affect abiotic stress resistance (including, but not limitedto, flowering, panicle/glume and seed development, enhancement ofnitrogen utilization efficiency, altered nitrogen responsiveness,drought resistance or tolerance, cold resistance or tolerance, and saltresistance or tolerance) and increased yield under stress. For example,see: Xiong, Lizhong, et al., “Disease Resistance and Abiotic StressTolerance in Rice Are Inversely Modulated by an Abscisic Acid-InducibleMitogen-Activated Protein Kinase,” The Plant Cell., 15:745-759 (2003),where OsMAPK5 can positively regulate drought, salt, and cold toleranceand negatively modulate PR gene expression and broad-spectrum diseaseresistance in rice; Chen, Fang, et. al., “The Rice 14-3-3 Gene Familyand its Involvement in Responses to Biotic and Abiotic Stress,” DNAResearch, 13(2):53-63 (2006), where at least four rice GF14 genes,GF14b, GF14c, GF14e, and Gf14f, were differentially regulated bysalinity, drought, wounding, and abscisic acid; PCT Publication No. WO00/73475 where water use efficiency is altered through alteration ofmalate; U.S. Pat. Nos. 5,892,009, 5,965,705, 5,929,305, 5,891,859,6,417,428, 6,664,446, 6,717,034, and 6,801,104, and PCT Publication Nos.WO 2000/060089, WO 2001/026459, WO 2001/035725, WO 2001/034726, WO2001/035727, WO 2001/036444, WO 2001/036597, WO 2001/036598, WO2002/015675, WO 2002/017430, WO 2002/077185, WO 2002/079403, WO2003/013227, WO 2003/013228, WO 2003/014327, WO 2004/031349, WO2004/076638, WO 98/09521, and WO 99/38977 describing genes, includingCBF genes and transcription factors effective in mitigating the negativeeffects of freezing, high salinity, and drought on plants, as well asconferring other positive effects on plant phenotype; U.S. PublicationNo. 2004/0148654 and PCT Publication No. WO 01/36596 where abscisic acidis altered in plants resulting in improved plant phenotype such asincreased yield and/or increased tolerance to abiotic stress; PCTPublication Nos. WO 2000/006341 and WO 04/090143, U.S. Publication No.2004/0237147, and U.S Pat. No. 6,992,237, where cytokinin expression ismodified resulting in plants with increased stress tolerance, such asdrought tolerance and/or increased yield. Also see, PCT Publication Nos.WO 02/02776, WO 2003/052063, WO 01/64898, JP 2002281975, and U.S. Pat.Nos. 6,084,153, 6,177,275, and 6,107,547 (enhancement of nitrogenutilization and altered nitrogen responsiveness). For ethylenealteration, see, U.S. Publication Nos. 2004/0128719 and 2003/0166197 andPCT Publication No. WO 2000/32761. For plant transcription factors ortranscriptional regulators of abiotic stress, see, e.g., U.S.Publication Nos. 2004/0098764 and 2004/0078852.

Other genes and transcription factors that affect plant growth andagronomic traits such as yield, flowering, plant growth, and/or plantstructure, can be introduced or introgressed into plants, see, e.g., PCTPublication Nos. WO 97/49811 (LHY), WO 98/56918 (ESD4), WO 97/10339, WO96/14414 (CON), WO 96/38560, WO 01/21822 (VRN1), WO 00/44918 (VRN2), WO99/49064 (GI), WO 00/46358 (FRI), WO 97/29123, WO 99/09174 (D8 and Rht),and U.S. Pat. Nos. 6,573,430 (TFL), 6,713,663 (FT), 6,794,560, 6,307,126(GAI), and PCT Publication Nos. WO 2004/076638 and WO 2004/031349(transcription factors).

Methods for Rice Transformation

Numerous methods for plant transformation have been developed, includingbiological and physical plant transformation protocols. See, forexample, Miki, et al., “Procedures for Introducing Foreign DNA intoPlants,” in Methods in Plant Molecular Biology and Biotechnology, Glickand Thompson Eds., CRC Press, Inc., Boca Raton, pp. 67-88 (1993)). Inaddition, expression vectors and in vitro culture methods for plant cellor tissue transformation and regeneration of plants are available. See,for example, Gruber, et al., “Vectors for Plant Transformation,” inMethods in Plant Molecular Biology and Biotechnology, Glick and ThompsonEds., CRC Press, Inc., Boca Raton, pp. 89-119 (1993).

A. Agrobacterium-mediated Transformation—One method for introducing anexpression vector into plants is based on the natural transformationsystem of Agrobacterium. See, for example, Horsch, et al., Science,227:1229 (1985). A. tumefaciens and A. rhizogenes are plant pathogenicsoil bacteria which genetically transform plant cells. The Ti and Riplasmids of A. tumefaciens and A. rhizogenes, respectively, carry genesresponsible for genetic transformation of the plant. See, for example,Kado, C. I., Crit. Rev. Plant Sci., 10:1 (1991). Descriptions ofAgrobacterium vector systems and methods for Agrobacterium-mediated genetransfer are provided by Gruber, et al., supra, Miki, et al., supra, andMoloney, et al., Plant Cell Reports, 8:238 (1989). See also, U.S. Pat.No. 5,591,616, issued January 7, 1997.

B. Direct Gene Transfer—Despite the fact the host range forAgrobacterium-mediated transformation is broad, some major cereal cropspecies and gymnosperms have generally been recalcitrant to this mode ofgene transfer, even though some success has recently been achieved inrice and corn. Hiei, et al., The Plant Journal, 6:271-282 (1994) andU.S. Pat. No. 5,591,616, issued Jan. 7, 1997. Several methods of planttransformation, collectively referred to as direct gene transfer, havebeen developed as an alternative to Agrobacterium-mediatedtransformation.

A generally applicable method of plant transformation ismicroprojectile-mediated transformation wherein DNA is carried on thesurface of microprojectiles measuring 1 to 4 μm. The expression vectoris introduced into plant tissues with a biolistic device thataccelerates the microprojectiles to speeds of 300 to 600 m/s which issufficient to penetrate plant cell walls and membranes. Sanford, et al.,Part. Sci. Technol., 5:27 (1987); Sanford, J. C., Trends Biotech., 6:299(1988); Klein, et al., Bio/Technology, 6:559-563 (1988); Sanford, J. C.,Physiol Plant, 7:206 (1990); Klein, et al., Biotechnology, 10:268(1992). In corn, several target tissues can be bombarded with DNA-coatedmicroprojectiles in order to produce transgenic plants, including, forexample, callus (Type I or Type II), immature embryos, and meristematictissue.

Another method for physical delivery of DNA to plants is sonication oftarget cells. Zhang, et al., Bio/Technology, 9:996 (1991). Additionally,liposome and spheroplast fusion have been used to introduce expressionvectors into plants. Deshayes, et al., EMBO J., 4:2731 (1985); Christou,et al., Proc Natl. Acad. Sci. U.S.A., 84:3962 (1987). Direct uptake ofDNA into protoplasts using CaCl₂ precipitation, polyvinyl alcohol orpoly-L-ornithine has also been reported. Hain, et al., Mol. Gen. Genet.,199:161 (1985) and Draper, et al., Plant Cell Physiol., 23:451 (1982).Electroporation of protoplasts and whole cells and tissues have alsobeen described. Dorm, et al., In Abstracts of VIIth InternationalCongress on Plant Cell and Tissue Culture IAPTC, A2-38, p. 53 (1990);D'Halluin, et al., Plant Cell, 4:1495-1505 (1992); and Spencer, et al.,Plant Mol. Biol., 24:51-61 (1994).

Following transformation of rice target tissues, expression of theabove-described selectable marker genes allows for preferentialselection of transformed cells, tissues, and/or plants usingregeneration and selection methods now well known in the art.

Genetic Marker Profile Through SSR and First Generation Progeny

In addition to phenotypic observations, a plant can also be identifiedby its genotype. The genotype of a plant can be characterized through agenetic marker profile which can identify plants of the same variety ora related variety or be used to determine or validate a pedigree.Genetic marker profiles can be obtained by techniques such as IsozymeElectrophoresis, Restriction Fragment Length Polymorphisms (RFLPs),Randomly Amplified Polymorphic DNAs (RAPDs), Arbitrarily PrimedPolymerase Chain Reaction (AP-PCR), DNA Amplification Fingerprinting(DAF), Sequence Characterized Amplified Regions (SCARs), AmplifiedFragment Length Polymorphisms (AFLPs), Simple Sequence Repeats (SSRs),which are also referred to as Microsatellites, and Single NucleotidePolymorphisms (SNPs). For example, see, Cregan et. al, “An IntegratedGenetic Linkage Map of the Soybean Genome,” Crop Science, 39:1464-1490(1999), and Berry, et al., “ssessing Probability of Ancestry UsingSimple Sequence Repeat Profiles: Applications to Maize Inbred Lines andSoybean Varieties,” Genetics, 165:331-342 (2003), each of which areincorporated by reference herein in their entirety.

Particular markers used for these purposes are not limited to anyparticular set of markers, but are envisioned to include any type ofmarker and marker profile which provides a means of distinguishingvarieties. One method of comparison is to use only homozygous loci forrice cultivar CL181-AR.

Primers and PCR protocols for assaying these and other markers arewidely known in the art. In addition to being used for identification ofrice cultivar CL181-AR and plant parts and plant cells of rice cultivarCL181-AR, the genetic profile may be used to identify a rice plantproduced through the use of rice cultivar CL181-AR or to verify apedigree for progeny plants produced through the use of rice cultivarCL181-AR. The genetic marker profile is also useful in breeding anddeveloping backcross conversions.

The present invention comprises a rice cultivar plant characterized bymolecular and physiological data obtained from the representative sampleof said cultivar deposited with the American Type Culture Collection(ATCC). Further provided by the invention is a rice hybrid plant formedby the combination of the disclosed rice plant or plant cell withanother rice plant or cell.

Means of performing genetic marker profiles using SSR polymorphisms arewell known in the art. SSRs are genetic markers based on polymorphismsin repeated nucleotide sequences, such as microsatellites. A markersystem based on SSRs can be highly informative in linkage analysisrelative to other marker systems in that multiple alleles may bepresent. Another advantage of this type of marker is that, through useof flanking primers, detection of SSRs can be achieved, for example, bythe polymerase chain reaction (PCR), thereby eliminating the need forlabor-intensive Southern hybridization. The PCR detection is done by useof two oligonucleotide primers flanking the polymorphic segment ofrepetitive DNA. Repeated cycles of heat denaturation of the DNA followedby annealing of the primers to their complementary sequences at lowtemperatures, and extension of the annealed primers with DNA polymerase,comprise the major part of the methodology.

Following amplification, markers can be scored by electrophoresis of theamplification products. Scoring of marker genotype is based on the sizeof the amplified fragment, which may be measured by the number of basepairs of the fragment. While variation in the primer used or inlaboratory procedures can affect the reported fragment size, relativevalues should remain constant regardless of the specific primer orlaboratory used. When comparing hybrids or varieties it is preferable ifall SSR profiles are performed in the same lab.

Primers used are publicly available and may be found in for example inU.S. Pat. Nos. 7,232,940, 7,217,003, 7,250,556, 7,214,851, 7,195,887,and 7,192,774.

In addition, plants and plant parts substantially benefiting from theuse of rice cultivar CL181-AR in their development, such as ricecultivar CL181-AR comprising a backcross conversion, transgene, orgenetic sterility factor, may be identified by having a molecular markerprofile with a high percent identity to rice cultivar CL181-AR. Such apercent identity might be 95%, 96%, 97%, 98%, 99%, 99.5%, or 99.9%identical to rice cultivar CL181-AR.

The SSR profile of rice cultivar CL181-AR also can be used to identifyessentially derived varieties and other progeny varieties developedusing rice cultivar CL181-AR, as well as cells and other plant partsthereof. Such plants may be developed using the markers identified inInternational Publication No. WO 00/31964, U.S. Pat. No. 6,162,967, andU.S. application Ser. No. 09/954,773. Progeny plants and plant partsproduced using rice cultivar CL181-AR may be identified by having amolecular marker profile of at least 25%, 30%, 35%, 40%, 45%, 50%, 55%,60%, 65%, 70%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or99.5% genetic contribution from a rice hybrid or variety, as measured byeither percent identity or percent similarity. Such progeny may befurther characterized as being within a pedigree distance of ricecultivar CL181-AR, such as within 1, 2, 3, 4, or 5 or fewercross-pollinations to a rice plant other than rice cultivar CL181-AR ora plant that has rice cultivar CL181-AR as a progenitor. Uniquemolecular profiles may be identified with other molecular tools such asSNPs and RFLPs.

While determining the S SR genetic marker profile of the plantsdescribed supra, several unique SSR profiles may also be identifiedwhich did not appear in either parent of such rice plant. Such uniqueSSR profiles may arise during the breeding process from recombination ormutation. A combination of several unique alleles provides a means ofidentifying a plant variety, an F₁ progeny produced from such variety,and progeny produced from such rice plan.

The foregoing methods for transformation would typically be used forproducing a transgenic cultivar. The transgenic cultivar could then becrossed, with another (non-transformed or transformed) cultivar, inorder to produce a new transgenic cultivar. Alternatively, a genetictrait which has been engineered into a particular rice cultivar usingthe foregoing transformation techniques could be moved into anothercultivar using traditional backcrossing techniques that are well knownin the plant breeding arts. For example, a backcrossing approach couldbe used to move an engineered trait from a public, non-elite cultivarinto an elite cultivar, or from a cultivar containing a foreign gene inits genome into a cultivar which does not contain that gene. As usedherein, “crossing” can refer to a simple X by Y cross, or the process ofbackcrossing, depending on the context.

Gene Conversion

When the term “rice plant” is used in the context of the presentinvention, this also includes any gene conversions of that cultivar. Theterm gene converted plant as used herein refers to those rice plantswhich are developed by a plant breeding technique called backcrossingwherein essentially all of the desired morphological and physiologicalcharacteristics of a cultivar are recovered in addition to the one ormore genes transferred into the cultivar via the backcrossing technique.Backcrossing methods can be used with the present invention to improveor introduce a characteristic into the cultivar. The term backcrossingas used herein refers to the repeated crossing of a hybrid progeny backto one of the parental rice plants, the recurrent parent, for thatcultivar, i.e., backcrossing 1, 2, 3, 4, 5, 6, 7, 8, 9, or more times tothe recurrent parent. The parental rice plant which contributes the genefor the desired characteristic is termed the nonrecurrent or donorparent. This terminology refers to the fact that the nonrecurrent parentis used one time in the backcross protocol and therefore does not recur.The parental rice plant to which the gene or genes from the nonrecurrentparent are transferred is known as the recurrent parent as it is usedfor several rounds in the backcrossing protocol (Poehlman & Sleper(1994); Fehr (1987)). In a typical backcross protocol, the originalcultivar of interest (recurrent parent) is crossed to a second cultivar(nonrecurrent parent) that carries the single gene or genes of interestto be transferred. The resulting progeny from this cross are thencrossed again to the recurrent parent and the process is repeated untila rice plant is obtained wherein essentially all of the desiredmorphological and physiological characteristics of the recurrent parentare recovered in the converted plant, in addition to one or moretransferred genes from the nonrecurrent parent as determined at the 5%significance level when grown in the same environmental conditions.

The selection of a suitable recurrent parent is an important step for asuccessful backcrossing procedure. The goal of a backcross protocol isto alter or substitute a single trait or characteristic in the originalcultivar. To accomplish this, one or more genes of the recurrentcultivar is modified or substituted with the desired gene or genes fromthe nonrecurrent parent, while retaining essentially all of the rest ofthe desired genetic, and therefore the desired physiological andmorphological, constitution of the original cultivar. The choice of theparticular nonrecurrent parent will depend on the purpose of thebackcross; one of the major purposes is to add some commerciallydesirable, agronomically important trait to the plant. The exactbackcrossing protocol will depend on the characteristic or trait beingaltered to determine an appropriate testing protocol. Althoughbackcrossing methods are simplified when the characteristic beingtransferred is a dominant allele, a recessive allele may also betransferred. In this instance it may be necessary to introduce a test ofthe progeny to determine if the desired characteristic has beensuccessfully transferred.

Many single gene traits have been identified that are not regularlyselected for in the development of a new cultivar but that can beimproved by backcrossing techniques. Single gene traits may or may notbe transgenic. Examples of these traits include but are not limited to,male sterility, waxy starch, herbicide resistance, resistance forbacterial, fungal, or viral disease, insect resistance, male fertility,enhanced nutritional quality, industrial usage, yield stability andyield enhancement. These genes are generally inherited through thenucleus. Some known exceptions to this are the genes for male sterility,some of which are inherited cytoplasmically, but still act as singlegene traits. Several of these single gene traits are described in U.S.Pat. Nos. 5,777,196, 5,948,957, and 5,969,212, the disclosures of whichare specifically hereby incorporated by reference.

Introduction of a New Trait or Locus into Rice Cultivar CL181-AR

Rice cultivar CL181-AR represents a new base genetic hybrid into which anew locus or trait may be introgressed. Direct transformation andbackcrossing represent two important methods that can be used toaccomplish such an introgression. The term backcross conversion andsingle locus conversion are used interchangeably to designate theproduct of a backcrossing program.

Backcross Conversions of Rice Cultivar CL181-AR

A backcross conversion of rice cultivar CL181-AR occurs when DNAsequences are introduced through backcrossing (Hallauer, et al., “CornBreeding,” Corn and Corn Improvements, No. 18, pp. 463-481 (1988)), withrice cultivar CL181-AR utilized as the recurrent parent. Both naturallyoccurring and transgenic DNA sequences may be introduced throughbackcrossing techniques. A backcross conversion may produce a plant witha trait or locus conversion in at least two or more backcrosses,including at least 2 crosses, at least 3 crosses, at least 4 crosses, atleast 5 crosses, and the like. Molecular marker assisted breeding orselection may be utilized to reduce the number of backcrosses necessaryto achieve the backcross conversion. For example, see, Openshaw, S. J.,et al., Marker-assisted Selection in Backcross Breeding, in: ProceedingsSymposium of the Analysis of Molecular Data, Crop Science Society ofAmerica, Corvallis, Oreg. (August 1994), where it is demonstrated that abackcross conversion can be made in as few as two backcrosses.

The complexity of the backcross conversion method depends on the type oftrait being transferred (single genes or closely linked genes as vs.unlinked genes), the level of expression of the trait, the type ofinheritance (cytoplasmic or nuclear) and the types of parents includedin the cross. It is understood by those of ordinary skill in the artthat for single gene traits that are relatively easy to classify, thebackcross method is effective and relatively easy to manage. (See,Hallauer, et al., in Corn and Corn Improvement, Sprague and Dudley,Third Ed. (1998)). Desired traits that may be transferred throughbackcross conversion include, but are not limited to, sterility (nuclearand cytoplasmic), fertility restoration, nutritional enhancements,drought tolerance, nitrogen utilization, altered fatty acid profile, lowphytate, industrial enhancements, disease resistance (bacterial, fungalor viral), insect resistance, and herbicide resistance. In addition, anintrogression site itself, such as an FRT site, Lox site, or other sitespecific integration site, may be inserted by backcrossing and utilizedfor direct insertion of one or more genes of interest into a specificplant variety. In some embodiments of the invention, the number of locithat may be backcrossed into rice cultivar CL181-AR is at least 1, 2, 3,4, or 5, and/or no more than 6, 5, 4, 3, or 2. A single locus maycontain several transgenes, such as a transgene for disease resistancethat, in the same expression vector, also contains a transgene forherbicide resistance. The gene for herbicide resistance may be used as aselectable marker and/or as a phenotypic trait. A single locusconversion of a site specific integration system allows for theintegration of multiple genes at the converted loci.

Tissue Culture

Further reproduction of the variety can occur by tissue culture andregeneration. Tissue culture of various tissues of rice and regenerationof plants therefrom is well known and widely published. For example,reference may be had to Komatsuda, T., et al., Crop Sci., 31:333-337(1991); Stephens, P. A., et al., Theor. Appl. Genet., 82:633-635 (1991);Komatsuda, T., et al., Plant Cell, Tissue and Organ Culture, 28:103-113(1992); Dhir, S., et al., Plant Cell Reports, 11:285-289 (1992); Pandey,P., et al., Japan J. Breed., 42:1-5 (1992); and Shetty, K., et al.,Plant Science, 81:245-251 (1992); as well as U.S. Pat. No. 5,024,944,issued Jun. 18, 1991 to Collins, et al., and U.S. Pat. No. 5,008,200,issued Apr. 16, 1991 to Ranch, et al. Thus, another aspect of thisinvention is to provide cells which upon growth and differentiationproduce rice plants having the physiological and morphologicalcharacteristics of rice variety CL181-AR.

As used herein, the term “tissue culture” indicates a compositioncomprising isolated cells of the same or a different type or acollection of such cells organized into parts of a plant. Exemplarytypes of tissue cultures are protoplasts, calli, plant clumps, and plantcells that can generate tissue culture that are intact in plants orparts of plants, such as embryos, pollen, flowers, seeds, pods, leaves,stems, roots, root tips, anthers, and the like. Means for preparing andmaintaining plant tissue culture are well known in the art. By way ofexample, a tissue culture comprising organs has been used to produceregenerated plants. U.S. Pat. Nos. 5,959,185; 5,973,234, and 5,977,445describe certain techniques, the disclosures of which are incorporatedherein by reference.

As used herein, the term “plant” includes plant cells, plantprotoplasts, plant cells of tissue culture from which rice plants can beregenerated, plant calli, plant clumps, and plant cells that are intactin plants or parts of plants, such as pollen, flowers, embryos, ovules,seeds, pods, leaves, stems, pistils, anthers, and the like. Thus,another aspect of this invention is to provide for cells which upongrowth and differentiation produce a cultivar having essentially all ofthe physiological and morphological characteristics of CL181-AR.

The present invention contemplates a rice plant regenerated from atissue culture of a variety (e.g., CL181-AR) or hybrid plant of thepresent invention. As is well known in the art, tissue culture of ricecan be used for the in vitro regeneration of a rice plant. Tissueculture of various tissues of rice and regeneration of plants therefromis well known and widely published. For example, reference may be had toChu, Q. R., et al., “Use of bridging parents with high antherculturability to improve plant regeneration and breeding value in rice,”Rice Biotechnology Quarterly, 38:25-26 (1999); Chu, Q. R., et al., “Anovel plant regeneration medium for rice anther culture of Southern U.S.crosses,” Rice Biotechnology Quarterly, 35:15-16 (1998); Chu, Q. R., etal., “A novel basal medium for embryogenic callus induction of SouthernUS crosses,” Rice Biotechnology Quarterly, 32:19-20 (1997); and Oono,K., “Broadening the Genetic Variability By Tissue Culture Methods,” Jap.J. Breed., 33 (Supp1.2), 306-307, illus. 1983. Thus, another aspect ofthis invention is to provide cells which upon growth and differentiationproduce rice plants having the physiological and morphologicalcharacteristics of variety CL181-AR.

Duncan, et al., Planta, 165:322-332 (1985), reflects that 97% of theplants cultured that produced callus were capable of plant regeneration.Subsequent experiments with both cultivars and hybrids produced 91%regenerable callus that produced plants. In a further study in 1988,Songstad, et al., Plant Cell Reports, 7:262-265 (1988), reports severalmedia additions that enhance regenerability of callus of two cultivars.Other published reports also indicated that “non-traditional” tissuesare capable of producing somatic embryogenesis and plant regeneration.K. P. Rao, et al., Maize Genetics Cooperation Newsletter, 60:64-65(1986), refers to somatic embryogenesis from glume callus cultures andB. V. Conger, et al., Plant Cell Reports, 6:345-347 (1987), indicatessomatic embryogenesis from the tissue cultures of corn leaf segments.Thus, it is clear from the literature that the state of the art is suchthat these methods of obtaining plants are routinely used and have avery high rate of success.

Tissue culture of corn is described in European Patent ApplicationPublication 160,390. Corn tissue culture procedures are also describedin Green and Rhodes, “Plant Regeneration in Tissue Culture of Maize,”Maize for Biological Research, Plant Molecular Biology Association,Charlottesville, Va., 367-372 (1982), and in Duncan, et al., “TheProduction of Callus Capable of Plant Regeneration from Immature Embryosof Numerous Zea Mays Genotypes,” 165 Planta, 322:332 (1985). Thus,another aspect of this invention is to provide cells which upon growthand differentiation produce corn plants having the physiological andmorphological characteristics of rice cultivar CL181-AR.

The utility of rice cultivar CL181-AR also extends to crosses with otherspecies. Commonly, suitable species will be of the family Graminaceae,and especially of the genera Zea, Tripsacum, Croix, Schlerachne,Polytoca, Chionachne, and Trilobachne, of the tribe Maydeae.

This invention also is directed to methods for producing a rice plant bycrossing a first parent rice plant with a second parent rice plantwherein the first or second parent rice plant is a rice plant of thevariety CL181-AR. Further, both first and second parent rice plants cancome from the rice variety CL181-AR. Thus, any such methods using therice variety CL181-AR are part of this invention: selfing, backcrosses,hybrid production, crosses to populations, and the like. All plantsproduced using rice variety CL181-AR as a parent are within the scope ofthis invention, including those developed from varieties derived fromrice variety CL181-AR. Advantageously, the rice variety could be used incrosses with other, different, rice plants to produce the firstgeneration (F₁) rice hybrid seeds and plants with superiorcharacteristics. The variety of the invention can also be used fortransformation where exogenous genes are introduced and expressed by thevariety of the invention. Genetic variants created either throughtraditional breeding methods using variety CL181-AR or throughtransformation of CL181-AR by any of a number of protocols known tothose of skill in the art are intended to be within the scope of thisinvention.

The following describes breeding methods that may be used with cultivarCL181-AR in the development of further rice plants. One such embodimentis a method for developing a CL181-AR progeny rice plant in a rice plantbreeding program comprising: obtaining the rice plant, or a partthereof, of cultivar CL181-AR utilizing said plant or plant part as asource of breeding material and selecting a CL181-AR progeny plant withmolecular markers in common with CL181-AR and/or with morphologicaland/or physiological characteristics selected from the characteristicslisted in Tables 2 or 3. Breeding steps that may be used in the riceplant breeding program include pedigree breeding, back crossing,mutation breeding, and recurrent selection. In conjunction with thesesteps, techniques such as RFLP-enhanced selection, genetic markerenhanced selection (for example SSR markers) and the making of doublehaploids may be utilized.

Another method involves producing a population of cultivar CL181-ARprogeny rice plants, comprising crossing cultivar CL181-AR with anotherrice plant, thereby producing a population of rice plants, which, onaverage, derive 50% of their alleles from cultivar CL181-AR. A plant ofthis population may be selected and repeatedly selfed or sibbed with arice cultivar resulting from these successive filial generations. Oneembodiment of this invention is the rice cultivar produced by thismethod and that has obtained at least 50% of its alleles from cultivarCL181-AR.

One of ordinary skill in the art of plant breeding would know how toevaluate the traits of two plant varieties to determine if there is nosignificant difference between the two traits expressed by thosevarieties. For example, see, Fehr and Walt, Principles of CultivarDevelopment, pp. 261-286 (1987). Thus the invention includes ricecultivar CL181-AR progeny rice plants comprising a combination of atleast two CL181-AR traits selected from the group consisting of thoselisted in the Tables herein, or the CL181-AR combination of traitslisted in the Summary of the Invention, so that said progeny rice plantis not significantly different for said traits than rice cultivarCL181-AR as determined at the 5% significance level when grown in thesame environment. Using techniques described herein, molecular markersmay be used to identify said progeny plant as a CL181-AR progeny plant.Mean trait values may be used to determine whether trait differences aresignificant, and preferably the traits are measured on plants grownunder the same environmental conditions. Once such a variety isdeveloped its value is substantial since it is important to advance thegermplasm base as a whole in order to maintain or improve traits such asyield, disease resistance, pest resistance, and plant performance inextreme environmental conditions.

Progeny of rice cultivar CL181-AR may also be characterized throughtheir filial relationship with rice cultivar CL181-AR, as for example,being within a certain number of breeding crosses of rice cultivarCL181-AR. A breeding cross is a cross made to introduce new geneticsinto the progeny, and is distinguished from a cross, such as a self or asib cross, made to select among existing genetic alleles. The lower thenumber of breeding crosses in the pedigree, the closer the relationshipbetween rice cultivar CL181-AR and its progeny. For example, progenyproduced by the methods described herein may be within 1, 2, 3, 4, or 5breeding crosses of rice cultivar CL181-AR.

Pedigree Breeding

Pedigree breeding starts with the crossing of two genotypes, such asrice cultivar CL181-AR and another rice plant having one or moredesirable characteristics that is lacking or which complements ricecultivar CL181-AR. If the two original parents do not provide all thedesired characteristics, other sources can be included in the breedingpopulation. In the pedigree method, superior plants are selfed andselected in successive filial generations. In the succeeding filialgenerations the heterozygous condition gives way to homogeneousvarieties as a result of self-pollination and selection. Typically inthe pedigree method of breeding, five or more successive filialgenerations of selfing and selection is practiced: F₁ to F₂; F₂ to F₃;F₃ to F₄; F₄ to F₅; etc. After a sufficient amount of inbreeding,successive filial generations will serve to increase seed of thedeveloped variety. Preferably, the developed variety compriseshomozygous alleles at about 95% or more of its loci.

In addition to being used to create a backcross conversion, backcrossingcan also be used in combination with pedigree breeding. As discussedpreviously, backcrossing can be used to transfer one or morespecifically desirable traits from one variety, the donor parent, to adeveloped variety called the recurrent parent, which has overall goodagronomic characteristics yet lacks that desirable trait or traits.However, the same procedure can be used to move the progeny toward thegenotype of the recurrent parent but at the same time retain manycomponents of the nonrecurrent parent by stopping the backcrossing at anearly stage and proceeding with selfing and selection. For example, arice variety may be crossed with another rice variety to produce a firstgeneration progeny plant. The first generation progeny plant may then bebackcrossed to one of its parent varieties to create a BC₁ or BC₂.Progeny are selfed and selected so that the newly developed variety hasmany of the attributes of the recurrent parent and yet several of thedesired attributes of the nonrecurrent parent. This approach leveragesthe value and strengths of the recurrent parent for use in new ricevarieties.

Therefore, an embodiment of this invention is a method of making abackcross conversion of rice cultivar CL181-AR, comprising the steps ofcrossing a plant of rice cultivar CL181-AR with a donor plant comprisinga desired trait, selecting an F₁ progeny plant comprising the desiredtrait, and backcrossing the selected F₁ progeny plant to a plant of ricecultivar CL181-AR. This method may further comprise the step ofobtaining a molecular marker profile of rice cultivar CL181-AR and usingthe molecular marker profile to select for a progeny plant with thedesired trait and the molecular marker profile of rice cultivarCL181-AR. In one embodiment the desired trait is a mutant gene ortransgene present in the donor parent.

Recurrent Selection and Mass Selection

Recurrent selection is a method used in a plant breeding program toimprove a population of plants. Rice cultivar CL181-AR is suitable foruse in a recurrent selection program. The method entails individualplants cross pollinating with each other to form progeny. The progenyare grown and the superior progeny selected by any number of selectionmethods, which include individual plant, half-sib progeny, full-sibprogeny and selfed progeny. The selected progeny are cross pollinatedwith each other to form progeny for another population. This populationis planted and again superior plants are selected to cross pollinatewith each other. Recurrent selection is a cyclical process and thereforecan be repeated as many times as desired. The objective of recurrentselection is to improve the traits of a population. The improvedpopulation can then be used as a source of breeding material to obtainnew varieties for commercial or breeding use, including the productionof a synthetic cultivar. A synthetic cultivar is the resultant progenyformed by the inter-crossing of several selected varieties.

Mass selection is a useful technique when used in conjunction withmolecular marker enhanced selection. In mass selection seeds fromindividuals are selected based on phenotype or genotype. These selectedseeds are then bulked and used to grow the next generation. Bulkselection requires growing a population of plants in a bulk plot,allowing the plants to self-pollinate, harvesting the seed in bulk andthen using a sample of the seed harvested in bulk to plant the nextgeneration. Also, instead of self pollination, directed pollinationcould be used as part of the breeding program.

Mutation Breeding

Mutation breeding is another method of introducing new traits into ricecultivar CL181-AR. Mutations that occur spontaneously or areartificially induced can be useful sources of variability for a plantbreeder. The goal of artificial mutagenesis is to increase the rate ofmutation for a desired characteristic. Mutation rates can be increasedby many different means including temperature, long-term seed storage,tissue culture conditions, radiation; such as X-rays, Gamma rays (e.g.,cobalt 60 or cesium 137), neutrons (product of nuclear fission byuranium 235 in an atomic reactor), Beta radiation (emitted fromradioisotopes such as phosphorus 32 or carbon 14), or ultravioletradiation (preferably from 2500 to 2900 nm), or chemical mutagens (suchas base analogues (5-bromo-uracil), related compounds (8-ethoxycaffeine), antibiotics (streptonigrin), alkylating agents (sulfurmustards, nitrogen mustards, epoxides, ethylenamines, sulfates,sulfonates, sulfones, lactones), azide, hydroxylamine, nitrous acid, oracridines. Once a desired trait is observed through mutagenesis thetrait may then be incorporated into existing germplasm by traditionalbreeding techniques. Details of mutation breeding can be found in“Principles of Cultivar Development,” Fehr, Macmillan Publishing Company(1983). In addition, mutations created in other rice plants may be usedto produce a backcross conversion of rice cultivar CL181-AR thatcomprises such mutation.

Breeding with Molecular Markers

Molecular markers may be used in plant breeding methods utilizing ricecultivar CL181-AR.

Isozyme Electrophoresis and RFLPs have been widely used to determinegenetic composition. See, for example, Dinka, S. J., et al., “Predictingthe size of the progeny mapping population required to positionallyclone a gene,” Genetics., 176(4):2035-54 (2007); Gonzalez, C., et al.,“Molecular and pathogenic characterization of new Xanthomonas oryzaestrains from West Africa,” Mol. Plant Microbe Interact., 20(5):534-546(2007); Jin, H., et al., “Molecular and cytogenic characterization of anOryza officinalis—O. sativa chromosome 4 addition line and itsprogenies,” Plant Mol. Biol., 62(4-5):769-777 (2006); Pan, G., et al.,“Map-based cloning of a novel rice cytochrome P450 gene CYP81A6 thatconfers resistance to two different classes of herbicides,” Plant Mol.Biol., 61(6):933-943 (2006); Huang, W., et al., “RFLP analysis formitochondrial genome of CMS-rice,” Journal of Genetics and Genomics.,33(4):330-338 (2007); Yan, C. J., et al., “Identification andcharacterization of a major QTL responsible for erect panicle trait injaponica rice (Oryza sativa L.),” Theor. Appl. Genetics.,DOI:10.1007/s00122-007-0635-9 (2007); and I. K. Vasil (ed.), DNA-basedmarkers in plants, Kluwer Academic Press Dordrecht, the Netherlands.

SSR technology is currently the most efficient and practical markertechnology; more marker loci can be routinely used and more alleles permarker locus can be found using SSRs in comparison to RFLPs. Gealy,David, et al., “Insights into the Parentage of Rice/red Rice CrossesUsing SSR Analysis of US Rice Cultivars and Red Rice Populations,” RiceTechnical Working Group Meeting Proceedings, Abstract, p. 179; Lawson,Mark J., et al., “Distinct Patterns of SSR Distribution in theArabidopsis thaliana and rice genomes,” Genome Biology., 7:R14 (2006);Nagaraju, J., et al., “Genetic Analysis of Traditional and EvolvedBasmati and Non-Basmati Rice Varieties by Using Fluorescence-basedISSR-PCR and SSR Markers,” Proc. Nat. Acad. Sci. USA., 99(9):5836-5841(2002); and Lu, Hong, et al., “Population Structure and BreedingPatterns of 145 US Rice Cultivars Based on SSR Marker Analysis,” CropScience, 45:66-76 (2005). Single Nucleotide Polymorphisms may also beused to identify the unique genetic composition of the invention andprogeny varieties retaining that unique genetic composition. Variousmolecular marker techniques may be used in combination to enhanceoverall resolution.

Rice DNA molecular marker linkage maps have been rapidly constructed andwidely implemented in genetic studies such as in Zhu, J. H., et al.,“Toward rice genome scanning by map-based AFLP fingerprinting,” Mol.Gene Genetics., 261(1):184-195 (1999); Cheng, Z., et al., “Toward acytological characterization of the rice genome,” Genome Research.,11(12):2133-2141 (2001); Alm, S., et al., “Comparative linkage maps ofthe rice and maize genomes,” Proc. Natl. Acad. Sci. USA,90(17):7980-7984 (1993); and Kao, F. I., et al., “An integrated map ofOryza sativa L. chromosome 5,” Theor. Appl. Genet., 112(5):891-902(2006). Sequences and PCR conditions of SSR Loci in rice as well as themost current genetic map may be found in RiceBLAST and the TIGR RiceGenome Annotation on the World Wide Web.

One use of molecular markers is Quantitative Trait Loci (QTL) mapping.QTL mapping is the use of markers, which are known to be closely linkedto alleles that have measurable effects on a quantitative trait.Selection in the breeding process is based upon the accumulation ofmarkers linked to the positive effecting alleles and/or the eliminationof the markers linked to the negative effecting alleles from the plant'sgenome.

Molecular markers can also be used during the breeding process for theselection of qualitative traits. For example, markers closely linked toalleles or markers containing sequences within the actual alleles ofinterest can be used to select plants that contain the alleles ofinterest during a backcrossing breeding program. The markers can also beused to select for the genome of the recurrent parent and against thegenome of the donor parent. Using this procedure can minimize the amountof genome from the donor parent that remains in the selected plants. Itcan also be used to reduce the number of crosses back to the recurrentparent needed in a backcrossing program. The use of molecular markers inthe selection process is often called genetic marker enhanced selection.Molecular markers may also be used to identify and exclude certainsources of germplasm as parental varieties or ancestors of a plant byproviding a means of tracking genetic profiles through crosses.

Production of Double Haploids

The production of double haploids can also be used for the developmentof plants with a homozygous phenotype in the breeding program. Forexample, a rice plant for which rice cultivar CL181-AR is a parent canbe used to produce double haploid plants. Double haploids are producedby the doubling of a set of chromosomes (1N) from a heterozygous plantto produce a completely homozygous individual. For example, see, Wan, etal., “Efficient Production of Doubled Haploid Plants Through ColchicineTreatment of Anther-Derived Maize Callus,” Theoretical and AppliedGenetics, 77:889-892 (1989), and U.S. Pat. No. 7,135,615.

Methods for obtaining haploid plants are also disclosed in Kobayashi,M., et al., Journ. of Heredity, 71(1):9-14 (1980), Pollacsek, M.,12(3):247-251, Agronomie, Paris (1992); Cho-Un-Haing, et al., Journ. ofPlant Biol., 39(3):185-188 (1996); Verdoodt, L., et al., 96(2):294-300(February 1998); Genetic Manipulation in Plant Breeding, ProceedingsInternational Symposium Organized by EUCARPIA, Berlin, Germany (Sept.8-13,1985); Thomas, W J K, et al., “Doubled haploids in breeding,” inDoubled Haploid Production in Crop Plants, Maluszynski, M., et al.(Eds.), Dordrecht, The Netherland Kluwer Academic Publishers, pp.337-349 (2003).

Descriptions of other breeding methods that are commonly used fordifferent traits and crops can be found in one of several referencebooks (e.g., Allard (1960); Simmonds (1979); Sneep, et al. (1979); Fehr(1987)).

The seed of rice cultivar CL181-AR, the plant produced from the cultivarseed, the hybrid rice plant produced from the crossing of the cultivar,hybrid seed, and various parts of the hybrid rice plant and transgenicversions of the foregoing, can be utilized for human food, livestockfeed, and as a raw material in industry.

The present invention provides methods for producing anherbicide-resistant rice plant through conventional plant breedinginvolving sexual reproduction. The methods comprise crossing a firstrice plant that is a plant of rice cultivar CL181-AR to a second riceplant that is not resistant to an herbicide. The methods of theinvention can further involve one or more generations of backcrossingthe progeny rice plants of the first cross to a rice plant of the sameline or genotype as either the first or second rice plant.Alternatively, the progeny of the first cross or any subsequent crosscan be crossed to a third rice plant that is of a different line orgenotype than either the first or second rice plant. The methods of theinvention can additionally involve selecting rice plants that comprisethe herbicide tolerance characteristics of the first rice plant.

The present invention further provides methods for increasing theherbicide-resistance of a rice plant, particularly anherbicide-resistant rice plant, through conventional plant breedinginvolving sexual reproduction. The methods comprise crossing a firstrice plant that is a plant of rice cultivar CL181-AR to a second riceplant that may or may not be resistant to the same herbicides as theplant of rice cultivar CL181-AR or may be resistant to differentherbicide or herbicides than the first rice plant. The progeny riceplants produced by this method of the present invention have increasedresistance to an herbicide when compared to either the first or secondrice plant or both. When the first and second rice plants are resistantto different herbicides, the progeny plants will have the combinedherbicide tolerance characteristics of the first and second rice plants.The methods of the invention can further involve one or more generationsof backcrossing the progeny rice plants of the first cross to a riceplant of the same line or genotype as either the first or second riceplant. Alternatively, the progeny of the first cross or any subsequentcross can be crossed to a third plant that is of a different line orgenotype than either the first or second plant. The methods of theinvention can additionally involve selecting rice plants that comprisethe herbicide tolerance characteristics of the first rice plant, thesecond rice plant, or both the first and the second rice plants.

TABLES

In Table 2, agronomic characteristics are shown for rice cultivarCL181-AR and for six other rice cultivars. These data are the result ofthe Arkansas Rice Performance Trials (ARPT) conducted in 2007.(Stuttgart, Rice Research and Extension Center (RREC); Keiser, NortheastResearch and Extension Center (NEREC); Rohwer, Southeast Research andExtension Center (SEREC-RD); Clay Co. and Jackson Co.). Column one showsthe variety, column two shows the yield in bushels per acre, columnthree shows the plant height in inches, column four shows the maturityin days at 50% heading, column five shows the kernel weight inmilligrams and column six shows the milling percent head rice (or wholekernel rice) as compared to the percent of total milled rice.

TABLE 2 Kernel Yield Height Maturity weight Milling Variety (BU/AC)(IN.) (50% HD) (mg) HR:TOT CL181-AR 162 32 89 18.1 55:69 CL 142-AR 19144 89 19.7 46:70 CL171-AR 167 39 90 16.7 57:71 CL161 155 38 89 16.761:70 Francis 185 38 87 17.2 53:70 Wells 185 41 88 18.7 48:70 Cocodrie163 36 88 17.9 61:70 C.V.₀₅ 10.3

In Table 3, agronomic characteristics are shown for rice cultivarCL181-AR and for seven other rice cultivars. These data are the resultof the Arkansas Rice Performance Trials (ARPT) conducted in 2008(Stuttgart, RREC; Keiser, NEREC; Rohwer, SEREC-RD; Clay Co. and JacksonCo.). Column one shows the variety, column two shows the yield inbushels per acre, column three shows the plant height in inches, columnfour shows the maturity in days at 50% heading, column five shows thekernel weight in milligrams and column six shows the milling percenthead rice (or whole kernel rice) as compared to the percent of totalmilled rice.

TABLE 3 Kernel Yield Height Maturity weight Milling Variety (BU/AC)(IN.) (50% HD) (mg) HR:TOT CL181-AR 152 35 92 18.8 59:71 CL 142-AR 15544 90 20.0 55:71 CL171-AR 136 39 91 17.4 57:72 CL161 142 38 91 16.160:71 CL131 138 33 87 17.5 63:73 Francis 170 39 90 17.4 62:72 Wells 16540 92 19.0 56:72 Cocodrie 148 36 88 17.7 63:72 C.V.₀₅ 12.1

In Table 4, agronomic characteristics are shown for rice cultivarCL181-AR and five other rice cultivars. These data are the result oftrials at the Arkansas Rice Performance Trials (ARPT) from 2007 to 2008.Column one shows the variety; column two gives the yield for eachvariety in bushels per acre; column three shows the height in inches forthe varieties; column four shows the maturity at 50% heading in days;column five gives the milled kernel weight in milligrams, and column sixgives the milling percent head rice (or whole kernel rice) as comparedto the percent of total milled rice.

TABLE 4 Kernel Yield Height Maturity weight Milling Variety (BU/AC)(IN.) (50% HD) (mg) HR:TOT CL181-AR 157 34 91 18.5 57:70 CL 142-AR 17344 90 19.9 50:71 CL171-AR 151 39 91 17.1 57:72 CL161 149 38 90 16.460:71 Francis 177 39 89 17.3 57:71 Wells 175 41 90 18.9 51:71 Cocodrie156 36 88 17.8 62:71

In Table 5, agronomic characteristics are shown for rice cultivarCL181-AR and six other rice cultivars. The data are the result of trialsat the Arkansas Rice Performance Trials (ARPT) from 2007. Column oneshows the variety, columns two to six give the average grain yield foreach of 5 different locations for each variety in bushels per acre,column eight gives the average grain yield for the 5 locations, columnseight to eleven show the average head rice (%) to total rice (%) ratiofor each of 4 different locations and column twelve shows the averagehead rice (%) to total rice (%) ratio for the 4 locations.

TABLE 5 Grain Yield (BU/AC)^(a) Head Rice(%):Total Rice(%)^(b) VarietyRREC NEREC SEREC-RD CC JC AVE RREC NEREC CC JC AVE CL181-AR 142 183 82187 218 162 60:70 50:67 57:70 55:71 55:69 CL 142-AR 171 182 150 204 251191 50:72 35:69 58:71 43:71 46:70 CL171-AR 142 180 105 197 210 167 63:7256:69 56:72 56:72 57:71 CL161 140 122 113 189 212 155 66:72 52:67 64:7164:71 61:70 Francis 199 93 163 218 249 185 62:72 43:68 57:71 55:71 53:70Wells 172 168 150 203 230 185 54:72 33:66 52:72 53:72 48:70 Cocodrie 176144 95 162 238 163 62:72 58:69 62:70 63:71 61:70 C.V._(.05) 5.3 16.213.6 8.4 7.8 10.3 ^(a)2007 consisted of five locations: Rice Researchand Extension Center (RREC), Stuttgart, AR; Northeast Research andExtension Center (NEREC), Keiser, AR; Southeast Research and ExtensionCenter Rohwer Division (SEREC-RD), Rohwer, AR; Clay County producerfield (CC); and Jackson County producer field (JC). ^(b)Milling figuresare head rice:total milled rice.

In Table 6, agronomic characteristics are shown for the presentinvention, CL181-AR and seven other rice cultivars. The data are theresult of trials at the Arkansas Rice Performance Trials (ARPT) from2008. Column one shows the variety, columns two to six give the averagegrain yield for each of 5 different locations for each variety inbushels per acre, column seven shows the average grain yield for the 5locations, columns eight to ten show the average head rice (%) to totalrice (%) ratio for each of 3 different locations and column eleven showsthe average head rice (%) to total rice (%) ratio for the 3 locations.

TABLE 6 Grain Yield (BU/AC)^(a) Head Rice(%):Total Rice(%)^(b) VarietyRREC PTES NEREC SEREC-RD JC AVE RREC NEREC JC AVE CL181-AR 152 152 184118 153 152 65:70 52:69 64:74 59:71 CL 142-AR 171 134 184 149 135 15562:70 55:71 49:72 55:71 CL171-AR 160 121 162 105 130 136 64:72 60:7250:71 57:72 CL161 176 117 146 119 153 142 66:71 64:73 51:70 60:71 CL131138 130 172 131 121 138 67:72 65:72 59:75 63:73 Francis 196 167 187 138163 170 63:70 59:71 64:74 62:72 Wells 194 177 172 151 133 165 66:7460:72 45:71 56:72 Cocodrie 158 150 173 117 144 148 66:71 67:74 58:7263:72 C.V._(.05) 5.4 7.7 13.6 11.9 12.6 12.1 ^(a)2008 consisted of fivelocations: Rice Research and Extension Center (RREC), Stuttgart; PineTree Experiment Station (PTES), Colt, AR; Northeast Research andExtension Center (NEREC), Keiser, AR; Southeast Research and ExtensionCenter Rohwer Division (SEREC-RD), Rohwer, AR; and Jackson Countyproducer field (JC). ^(b)Milling figures are head rice:total milledrice.

In Table 7, agronomic characteristics are shown for rice cultivarCL181-AR, and six other rice cultivars. The data are the result of anaverage of the trials at the Arkansas Rice Performance Trials (ARPT)from 2007 to 2008. Column one shows the variety, columns two to sevengive the average grain yield for each of 6 different locations for eachvariety in bushels per acre, column eight shows the average grain yieldfor the 6 locations, columns nine to twelve show the average head rice(%) to total rice (%) ratio for each of 4 different locations and columnthirteen shows the average head rice (%) to total rice (%) ratio for the4 locations.

TABLE 7 Grain Yield (BU/AC)^(a) Head Rice(%):Total Rice(%)^(b) VarietyRREC PTES NEREC SEREC-RD CC JC AVE RREC NEREC CC JC AVE CL181-AR 147 152184 100 187 186 157 63:70 51:68 57:70 60:73 57:70 CL 142-AR 171 134 183150 204 193 173 56:71 45:70 58:71 46:72 50:71 CL171-AR 151 121 171 105197 170 151 64:72 58:71 56:72 53:72 57:72 CL161 158 117 134 116 189 183149 66:72 58:70 64:71 57:71 60:71 Francis 197 167 140 151 218 206 17763:71 51:69 57:71 60:73 57:71 Wells 183 177 170 151 203 182 175 60:7346:69 52:72 49:72 51:71 Cocodrie 167 150 159 106 162 191 156 64:72 62:7162:70 61:72 62:71 ^(a)2007 consisted of six locations: Rice Research andExtension Center (RREC), Stuttgart, AR; Northeast Research and ExtensionCenter (NEREC), Keiser, AR; Southeast Research and Extension CenterRohwer Division (SEREC-RD), Rohwer, AR; Clay County producer field (CC);and Jackson County producer field (JC); and 2008 RREC, Pine TreeExperiment Station (PTES), Colt, AR; NEREC, SEREC-RD, and JC.^(b)Milling figures are head rice:total milled rice.

In Table 8, agronomic characteristics are shown for rice cultivarCL181-AR and 5 other rice cultivars. The data are results of trials fromthe Clearfield Arkansas Rice Performance Trials (ARPT) conducted in2007. Column one shows the variety, columns two to three show the grainyield in bushels per acre for 2 locations, column four shows the averagegrain yield for the 2 locations, column five shows the height in inches,column six shows the maturity in number of days from emergence to 50%heading, columns seven to eight show the percent lodging for 2locations, column nine shows the average % lodging for the 2 locations,columns ten to eleven show the head rice (%) to total rice (%) ratio for2 locations and column twelve shows the average head rice (%) to totalrice (%) ratio for the 2 locations.

TABLE 8 Grain Yield (BU/AC)^(a) HGT^(c) MAT.^(d) % Lodging^(e) Milling(HR:TOT)^(f) Variety RREC^(b) NEREC AVE (IN.) (50% HD) RREC NEREC AVERREC NEREC AVE CL181-AR 155 210 182 37 87 0 10 5 57:70 60:70 59:70 CL142-AR 122 165 143 47 88 25 63 44 42:73 42:70 42:71 CL171-AR 130 177 15341 90 25 33 29 60:72 57:71 58:72 CL161 99 101 100 40 89 67 57 62 62:7060:70 61:70 CLXL729 124 87 105 42 86 67 43 55 52:70 45:68 49:69 CLXL73093 85 89 44 86 44 78 80 52:72 46:69 49:70 ^(a)Rice Research andExtension Center (RREC), Stuttgart, AR and Northeast Research andExtension Center (NEREC), Keiser, AR. ^(b)RREC was planted mid May andrain and wind caused delayed harvest and lodging; shattering was aproblem for hybrids. ^(c)HGT is height in inches. ^(d)MAT is maturitynumber of days from emergence to 50% heading. ^(e)NEREC was planted onApril 30 and could not be harvested on time due to rains and a stormcaused tremendous lodging. Shattering was a problem for the hybridlines. ^(f)Milling figures are head rice:total milled rice ratio.

In Table 9, agronomic characteristics are shown for rice cultivarCL181-AR and 5 other rice cultivars. The data are results of trials fromthe Clearfield Arkansas Rice Performance Trials (ARPT) conducted in2008. Column one shows the variety, columns two to three show the grainyield in bushels per acre for 2 locations, column four shows the averagegrain yield for the 2 locations, column five shows the height in inches,column six shows the maturity in number of days from emergence to 50%heading, columns seven to eight show the percent lodging for 2locations, column nine shows the average % lodging for the 2 locations,columns ten to eleven show the head rice (%) to total rice (%) ratio for2 locations and column twelve shows the average head rice (%) to totalrice (%) ratio for the 2 locations.

TABLE 9 Grain Yield (BU/AC)^(a) HGT^(c) MAT.^(d) % Lodging Milling(HR:TOT)^(e) Variety RREC LK^(b) AVE (IN.) (50% HD) RREC PC AVE RREC LKAVE CL181-AR 190 113 152 34 95 0 0 0 69:72 64:74 67:73 CL 142-AR 178 103140 40 94 27 0 13 68:74 62:76 65:75 CL171-AR 155 99 127 38 96 0 0 067:72 67:76 67:74 CL161 177 106 142 39 95 17 0 8 70:73 68:77 69:75 CL131170 111 141 34 92 3 0 2 70:75 71:77 70:76 CL151 195 109 152 36 93 60 030 68:73 59:74 63:73 ^(a)Rice Research and Extension Center (RREC),Stuttgart, AR and University of Arkansas Pine Bluff Farm (LK), Lonoke,AR. ^(b)LK was planted late on Jun. 5, 2008. ^(c)HGT is height ininches. ^(d)MAT is maturity number of days from emergence to 50%heading. ^(e)Milling figures are head rice:total milled rice ratio.

In Table 10, agronomic characteristics are shown for rice cultivarCL181-AR and 3 other rice cultivars. The data are averages of resultsfrom the Clearfield Arkansas Rice Performance Trials (ARPT) conductedfrom 2007 to 2008. Column one shows the variety, columns two to fourshow the grain yield in bushels per acre for 3 locations, column fiveshows the average grain yield for the 3 locations, column six shows theheight in inches, column seven shows the maturity in number of days fromemergence to 50% heading, columns eight to ten show the head rice (%) tototal rice (%) ratio for 3 locations and column eleven shows the averagehead rice (%) to total rice (%) ratio for the 3 locations.

TABLE 10 Grain Yield (BU/AC)^(a) HGT^(b) MAT.^(c) Milling (HR:TOT)^(d)Variety RREC NEREC LK AVE (IN.) (50% HD) RREC NEREC LK AVE CL181-AR 173210 113 167 36 91 63:71 60:70 64:74 63:72 CL 142-AR 150 165 103 142 4491 55:74 42:70 62:76 54:78 CL171-AR 143 177 99 140 40 93 64:72 57:7167:76 63:73 CL161 138 101 106 121 40 92 66:72 60:70 68:77 65:73 ^(a)RiceResearch and Extension Center (RREC), Stuttgart, AR (2007-2008);Northeast Research and Extension Center (NEREC), Keiser, AR (2007); andUniversity of Arkansas Pine Bluff Farm (LK), Lonoke, AR (2008). ^(b)HGTis height in inches. ^(c)MAT is maturity number of days from emergenceto 50% heading. ^(d)Milling figures are head rice:total milled riceratio.

In Table 11, kernel characteristics are shown for rice cultivarsCL181-AR and CL181-AR. The data are averages of the following trials,2005 IMI SIT RREC, 2006 IMI SIT, RREC, 2007 ARPT and IMI ARPT, RREC,2008 ARPT and IMI ARPT and 2008 Breeder Head Row Seed RREC. Column 1shows the variety, column 2 shows the class, column 3 shows the lengthin millimeters, column 4 shows the width in millimeters, column 5 showsthe thickness in millimeters, column 6 shows the length to width ratioand column 7 shows the kernel weight in milligrams. The numbers in thetables are averages for the tests listed. Rice cultivar CL 142-AR had arange of 25.5 to 29.5 mg/kernel in these tests and CL181-AR had a rangeof 22.0 to 26.5 mg/kernel for the same tests.

TABLE 11 Variety Class Length Width Thickness L/W Kernel CL142-AR Rough9.08 2.64 2.01 3.44 26.9 CL181-AR Rough 8.96 2.47 1.97 3.63 24.2CL142-AR Brown 7.28 2.38 1.76 3.06 23.3 CL181-AR Brown 7.08 2.29 1.733.09 19.6 CL142-AR Milled 6.80 2.24 1.70 3.04 20.4 CL181-AR Milled 6.682.14 1.67 3.12 17.9

Disease Evaluations for Rice Cultivar CL181-AR Greenhouse Blast Tests

Rice diseases are usually rated visually on a 0-9 scale to estimatedegree of severity. Numerical data is often converted to this scale. Arating of zero indicates complete disease immunity. A rating of one tothree indicates resistance where little loss occurs and in the case ofrice blast pathogen growth is restricted considerably. Conversely, anine rating indicates maximum disease susceptibility, which typicallyresults in complete plant death and/or yield loss. Depending upon thedisease in question, a disease rating of four to six is usuallyindicative of acceptable disease resistance under conditions slightlyfavoring the pathogen. Numerical ratings are sometimes converted toletter symbols where 0-3=R (resistant), 3-4=MR (moderately resistant),5-6=MS (moderately susceptible) 7=S (susceptible) and 8-9 VS (verysusceptible). Exceptions to established ratings do occur unexpectedly asdisease situations change.

Greenhouse blast tests are the primary means of screening large numberof entries for varietal reaction to the many blast races occurring inthe production areas. Although results are quite variable and testingconditions tends to overwhelm any field resistance present in the entry,this test provides an accurate definition of the fungus-varietygenetics. Blast field nurseries, utilizing both natural and lab producedinoculum, are established in an effort to better define blastsusceptibility under field conditions. Since field nursery is also quitevariable, new techniques are currently being developed and evaluated tobetter estimate cultivar field resistance to blast.

Tables 12 and 13 are summaries of available leaf blast rating data^(a)from CL181-AR and seven comparison plants inoculated with the indicatedrace using standard greenhouse techniques.^(b) Data were taken from 2007to 2008.

For Table 12, column one shows the variety and columns two to nine showleaf blast rating data of each race for each variety.

For Table 13, column one shows the variety name, columns two to threeshows the leaf blast rating data, column four shows the panicle blastrating data and column five shows the sheath blight data.

TABLE 12 2008/07 Greenhouse Blast Race Leaf Assays Ave. IB-1 Ave. IB-49Ave. IC-17 Ave. IE-1 Ave. IG-1 Ave. IH-1 Ave. IE-1k Ave. IB-33 Variety(ZN-15) (ZN-61) (ZN-1) (ZN-6) (ZN-39) (74L2) (ZN-19) (FL9) CL181-AR 5.57.7 7.7 3.7 5.7 0.7 6.7 6.3 S VS VS MR S R S S CL 142-AR 5.8 7.8 8.0 5.00.8 0.3 6.3 6.7 S VS VS MS R R S S CL131 0.0 0.0 1.3 0.0 0.3 0.7 4.3 6.3R R R R R R S S CL161 6.5 8.0 8.0 3.8 1.2 0.7 6.0 7.7 S VS VS MR R R SVS CL171-AR 6.3 7.5 8.0 3.7 0.5 0.0 7.7 7.0 S VS VS MR R R VS S Cybonnet0.9 0.2 0.7 0.1 0.1 0.0 7.0 6.2 R R R R R R S S Francis 6.5 7.8 7.8 4.76.8 1.1 7.3 7.3 S VS VS MS S R VS VS Wells 6.0 7.7 8.1 4.7 2.1 0.1 5.27.7 S VS VS MS R R S VS

TABLE 13 2008/07 Field Summary 2008/07 2008 2008/07 PTES PTES PD2* PTES2008/07 Leaf Blast Leaf Blast Panicle Blast Sheath Blight VarietyAverage Average Average Average CL181-AR 4.0 6.5 6.6 7.4 S S-VS S-VS VSCL 142-AR 4.6 7.3 7.2 5.7 S S-VS S-VS MS CL131 1.0 2.3 0.0 8.3 R R R VSCL161 4.3 6.8 5.6 7.3 S S-VS S VS CL171-AR 4.6 7.0 5.9 7.0 S S-VS S-VSS-VS Cybonnet 1.0 3.3 2.5 7.1 R R R S-VS Francis 5.4 7.0 7.0 6.7 S S-VSS-VS S Wells 4.5 6.5 5.5 6.3 S S-VS S S

Physiological Evaluations for Rice Cultivar CL181-AR Straighthead

Straighthead is a physiological disorder which appears to be effected bythe oxygen potential of the soil. Under certain conditions, arseniclevels can increase in these soils or on soils where cotton has beengrown and MSMA or other arsenical pesticides have been applied.Straighthead may also occur in soils high in organic matter. Symptomscan only be detected after panicle emergence and fail to produce grain.Foliage tends to remain dark green. Rice grains may be distortedespecially on long-grain varieties forming a parrot-beak on the end ofthe hull. Floral parts may also be missing and under severe conditionspanicle fail to emerge from the boot.

In Table 14, the reaction of CL181-AR to Straighthead is compared tovarious rice cultivars in three separate trials from 2007 and 2008 inStuttgart, Ark. Column one shows the variety, column two shows therating from 2007, column three shows the rating from 2008 and columnfour shows the rating taken as an average from 2007 to 2008.

TABLE 14 Variety 2007² 2008² Average CL181-AR 3.3 4.0 3.7 CL 142-AR 5.05.7 5.4 CL171-AR 5.3 6.0 5.7 CL161 5.3 5.3 5.3 CL131 7.0 — Francis 4.74.7 4.7 Wells 6.3 6.7 6.5 LaGrue 6.3 6.0 6.2 Cybonnet 3.7 4.7 4.2Cocodrie 7.0 7.3 7.2 ¹Based on a scale of 0 to 9 where 0 = no symptomsand 9 = no grain formation. Rating Scale: 0 = no damage 1 = 81-90% graindevelop 2 = 71-80% grain develop and 96-100% panicles broken fromvertical 3 = 61-80% grain develop and 91-95% panicles broken fromvertical 4 = 41-60% grain develop and 61-90% panicles broken fromvertical 5 = 21-40% grain develop and 31-60% panicles broken fromvertical - initial appearance of parrot-beak distortion 6 = 11-20% graindevelop and 10-30% panicles broken from vertical 7 = panicles emergedbut totally upright; only 0-10% grain develop 8 = 0-10% panicleemergence, no seed produced 9 = no panicles ²Average of 3 repetitions.

Clearfield Disease Evaluations

Tables 15 and 16 provide rough rice grain yield in bushels per acre from2007 to 2008 from the Disease Monitoring Plots treated with theherbicide NEWPATH, and located in four Arkansas counties.

TABLE 15 2007 Locations Variety Jackson Lincoln Phillips Prairie MeanC.V. CL181-AR 93 148 158 137 134 21.5 CL 142-AR 100 170 141 137 137 20.9CL161 91 148 132 123 123 19.7 CL171-AR 100 153 131 115 125 18.5 RTCLXL729 151 192 204 191 185 12.6 RT CLXL730 153 180 144 175 163 10.8 RTCLXP745 150 150 172 170 161 7.6 Mean 96 147 119 125 122 LSD 16 15.7 20.116 C.V. 9.8 6.3 9.2 7.2

TABLE 16 2008 Locations Variety Craighead Lincoln Poinsett Mean C.V.CL181-AR 176 194 190 187 5.0 CL 142-AR 178 206 197 194 7.2 CL131 178 179160 172 6.0 CL151 172 190 171 178 6.2 CL161 168 196 174 180 8.1 CL171-AR156 186 166 169 8.9 RT CLXL729 213 223 218 218 2.3 RT CLXL730 182 204188 192 6.0 RT CLXL745 207 220 190 206 7.1 RT CLXP746 212 220 182 2059.9 Mean 167 191 183 181 LSD 43.7 19.7 27.4 C.V. 15.8 6.3 9.1

Deposit Information

A deposit of the University of Arkansas proprietary rice cultivardesignated CL181-AR disclosed above and recited in the appended claimshas been made with the American Type Culture Collection (ATCC), 10801University Boulevard, Manassas, Va. 20110. The date of deposit was May12, 2010. The deposit of 2,500 seeds was taken from the same depositmaintained by University of Arkansas, Rice Research and Extension Centersince prior to the filing date of this application. All restrictionsupon the deposit have been removed, and the deposit is intended to meetall of the requirements of 37 C.F.R. 1.801-1.809. The ATCC accessionnumber is PTA-10948. The deposit will be maintained in the depositoryfor a period of 30 years, or 5 years after the last request, or for theeffective life of the patent, whichever is longer, and will be replacedas necessary during that period.

While a number of exemplary aspects and embodiments have been discussedabove, those of skill in the art will recognize certain modifications,permutations, additions and sub-combinations thereof. It is thereforeintended that the following appended claims and claims hereafterintroduced are interpreted to include all such modifications,permutations, additions and sub-combinations as are within their truespirit and scope.

1-43. (canceled)
 44. A method for controlling weeds in the vicinity ofrice, comprising contacting the rice with an herbicide, wherein saidrice is (a) rice cultivar CL181-AR or (b) a hybrid, derivative, orprogeny of rice cultivar CL181-AR that expresses the imidazolinoneherbicide resistance characteristics of rice cultivar CL181-AR, andwherein a representative sample of seed of rice cultivar CL181-AR wasdeposited under ATCC Accession No. PTA-10948.
 45. The method accordingto claim 44, wherein the herbicide is an herbicide imidazolinone, asulfonylurea herbicide, or a combination thereof.
 46. The methodaccording to claim 44, wherein the rice is a rice plant and saidcontacting comprises applying the herbicide in the vicinity of the riceplant.
 47. The method according to claim 46, wherein said herbicide isapplied to weeds in the vicinity of the rice plant.
 48. The methodaccording to claim 44, wherein the rice is a rice seed and saidcontacting comprises applying the herbicide to the rice seed.
 49. Amethod for treating rice, comprising contacting the rice with anagronomically acceptable composition, wherein said rice is (a) ricecultivar CL181-AR or (b) a hybrid, derivative, or progeny of ricecultivar CL181-AR that expresses the imidazolinone herbicide resistancecharacteristics of rice cultivar CL181-AR, and wherein a representativesample of seed of rice cultivar CL181-AR was deposited under ATCCAccession No. PTA-10948.
 50. The method according to claim 49, whereinthe agronomically acceptable composition comprises at least oneagronomically acceptable active ingredient.
 51. The method according toclaim 50, wherein the agronomically acceptable active ingredient isselected from the group consisting of fungicides, insecticides,antibiotics, stress tolerance-enhancing compounds, growth promoters,herbicides, molluscicides, rodenticides, and animal repellants, andcombinations thereof.